Virginia Land Snails
GENERIC KEYS:
Anguispira
Carychium
Catinella
Cepaea
Cochlicopa
Discus
Euchemotrema
Euconulus
Gastrocopta
Gastrodonta
Glyphyalinia
Hawaiia
Helicodiscus
Inflectarius
Lucilla
Mesodon
Mesomphix
Neohelix
Nesovitrea
Novisuccinea
Oxychilus
Oxyloma
Paravitrea
Patera
Pomatiopsis
Punctum
Stenotrema
Striatura
Strobilops
Succinea
Triodopsis
Vallonia
Ventridens
Vertigo
Zonitoides
Key to shelled land snails of Virginia
(adult shells only)
by Ken Hotopp, with pupillids by Jeff Nekola
1a. Shell wider than tall, or approximately as wide as tall
Go to 2
1b. Shell taller than wide
Go to 43
2a. Shell with thickened or reflected peristome (mostly or entirely reflected, narrowly or widely)
Go to 3
2b. Shell with thin peristome (though may be callused or toothed within)
Go to 23
3a. Shell diameter <4mm
Go to 4
3b. Shell diameter >4mm
Go to 5
4a. Shell flattened, depressed
Vallonia
4b. Shell taller, low conical
Strobilops
5a. Shell texture of radial ridges, or a fuzzy hair-like texture
Go to 6
5b. Shell sculpture fine radial striae; shell imperforate and dome-shaped
Hendersonia occulta
6a. Shell umbilicate
Go to 7
6b. Shell imperforate or rimate
Go to 13
7a. Shell with teeth in aperture
Go to 9
7b. Shell without pronounced teeth in aperture
Go to 8
8a. Peristome with basal swelling; spiral stripe in fresh shells
Allogona profunda
8b. Peristome without basal swelling; tubular whorls
Haplotrema concavum
9a. Shell with a parietal tooth only
Go to 10
10b. Shell with two or three teeth
Go to 11
10a. Larger shell (>14mm), small parietal tooth
Fumonelix wheatleyi
10b. Small shell (<8mm), sinuous peristome continuous with parietal tooth.
Daedalochila plicata
11a. Shell with parietal tooth and spike-like basal tooth; larger (>18 mm diameter)
Appalachina sayana
11b. Shell with three teeth
Go to 12
12a. Very small shell <6 mm wide; fresh shell with sparse “hairs”
Lobosculum pustuloides
12b. Shell >6 mm wide; no hairs
Triodopsis
13a. Shell flatter, depressed
Go to 14
13b. Shell taller, domed or rounded
Go to 17
14a. Shell with short parietal lamella
Go to 16
14b.Shell with long parietal lamella
Go to 15
15a. Shell with subtle basal lamella, no palatal tooth
Patera
15b. Shell with pronounced basal lamella, palatal tooth
Xolotrema denotata
16a. Shell less than 11mm diameter
Fumonelix christyi
16b. Shell more than 19mm diameter
Neohelix dentifera
17a. Shell with long parietal tooth, narrow or slit-like aperture
Go to 18
17b. All others, with or without teeth
Go to 19
18a. Sinuous and notched basal lamella, covered umbilicus
Stenotrema
18b. No basal lamella, rimate umbilicus
Euchemotrema
19a. Peristome widely reflected, shells not banded
Go to 20
19b. Peristome narrowly reflected, fresh shells usually banded
Go to 21
20a. Shells smaller than 15mm wide
Inflectarius
20b. Shells larger than 15mm wide
Mesodon and Neohelix
21a. Rib-like callus just within aperture
Cernuella virgata
21b. No rib-like callus
Go to 22
22a. Shell >25mm wide, light-colored with broken stripes
Helix aspersa
22b. Shell 25 mm wide or less, yellowish with dark continuous stripes, or no stripes
Cepaea
23a. Shells >4mm wide
Go to 24
23b. Shells <4mm wide
Go to 35
24a. Shell between 4-16mm diameter
Go to 25
24b. Shell >16mm diameter
Go to 32
25a. Shells with engraved radial grooves
Glyphyalinia and Nesovitrea
25b. Shells without radial grooves, but may have radial ridges or other sculpture
Go to 26
26a. Shells with very strong radial ribs, coarse texture above and below
Discus
26b. All others - shells with weak to smooth sculpture, or with spiral sculpture, or with coarse sculpture only on upper surface
Go to 27
27a. Shell having heavy callus or lamellae within aperture
Go to 28
27b. Shells without heavy callus or lamellae in aperture.
Go to 29
28a. Shell tightly whorled, with coarse radial sculpture on upper surfaces
Gastrodonta
28b. Shell regularly whorled, without coarser sculpture above
Ventridens
29a. Shell imperforate, very rapidly expanding, amber-colored and fragile
Vitrinzonites latissimus
29b. Shells perforate or umbilicate
Go to 30
30a. Umbilicus < ¼ shell diameter, shell very tightly coiled, internal teeth sometimes visible through base
Paravitrea (most)
30b. Umbilicus > ¼ shell diameter, shell regularly or rapidly expanding
Go to 31
31a. Shell rapidly expanding, wider umbilicus
Oxychilus
31b. Shell regularly expanding, well-like umbilicus
Zonitoides
32a. Smooth or finely-textured shell
Go to 33
32b. Shell with strong radial ribs
Go to 34
33a. Shells with two brown spiral bands
Anguispira kochi
33b. Unbanded shells
Mesomphix
34a. Shell with a heavy, rib-like callus within the aperture
Candidula intersecta
34b. Shell lacking a transverse callus within the aperture
Anguispira (most species)
35a. Shell with wide umbilicus, tubular whorls, low apex
Go to 36
35b. All others
Go to 39
36a. Shells with spiral lirae or fringes, which may be faint
Go to 37
36b. Shells lacking spiral lirae or fringes
Go to 38
37a. Shells with simple final whorl
Helicodiscus
37b. Shells with deflected final whorl bearing a parallel lamella
Polygyriscus virginianus
38a. Shell with fine radial and spiral striae, silky texture
Hawaiia
38b. Shell glossy with rounded growth wrinkles
Lucilla
39a. Shell imperforate
Guppya sterkii
39b. Shell umbilicate
Go to 40
40a. Shell almost as tall as wide, beehive-shaped
Euconulus
40b. Shell flatter in profile
Go to 41
41a. Shell tightly whorled, internal teeth visible through base
Paravitrea (in part)
41b. All others
Go to 42
42a. Shell regularly-coiled, whorls increasing <1.5x per revolution
Punctum
42b. Shell more loosely coiled, whorls increasing >1.5x per revolution
Striatura
43a. Shell with narrow aperture parallel to column; coastal
Melampus bidentatus
43b. All others
Go to 44
44a. Relaxed spiral with no more than 3 whorls in mature shell
Go to 45
44b.Tighter spiral with 4+ whorls in mature shell
Go to 48
45a. Aperture taking up ½ of shell length
Catinella
45b. Aperture more than ½ of shell length
Go to 46
46a. Shell and aperture narrowly ovate to elongate
Oxyloma
46b.Shell and aperture broadly ovate
Novisuccinea and Succinea
47a. Shell very glossy, transparent, cylindrical, at least 4mm tall
Go to 48
47b. Shell silky to dull, opaque
Go to 49
48a. Shell yellowish or brown
Cochlicopa
48b. Shell whitish or clear
Go to 50
49a. Shell smooth, glossy; up to 5.5 mm tall
Cecilioides acicula
49b. Shell textured with fine radial lines; up to 8mm tall
Opeas pyrgula
50a.Shell cone-shaped, with pointed apex, at least 4 mm tall
Go to 51
50b.Shell pupa-shaped, columnar, or spike-shaped
Go to 52
51a. Shell brown with thickened, light-colored peristome
Pupoides albilabris
51b. Shell brown with thin peristome and impressed sutures
Pomatiopsis
52a. Shell very narrow, at least 2½ times taller than wide, white
Carychium
52b. Shell 1½-2½ times taller than wide
Go to 53
53a. At least one lamella in aperture
Go to 54
53b. No apertural lamella
Go to 56
54a. Parietal lamella fused with angular forming a complex bilobed structure
Gastrocopta
54b. Parietal lamella a simple peg or plate (occasionally absent); angular lamellae (if present) not fused with the parietal
Go to 55
55a. Fresh shells waxy white to clear
Gastrocopta
55b. Fresh shells pale yellow to deep reddish brown
Vertigo
56a. Shell >3 mm tall
Pupilla muscorum
56b. Shell <3 mm tall
Go to 57
57a. Shell with fewer than 4 whorls
immature pupillid
57b. Shell with 4 or more whorls
Columella simplex
Anguispira (most species: alternata, fergusoni, jessica, mordax, rugoderma, strongylodes; not including kochi)
1a. Ribs very coarse, from 0.5-1.0 mm apart; central or western
A. mordax
1b. Ribs moderately coarse
Go to 2
2a. Shell colorful - background color slightly yellowish, with reddish spots; mucus clear; eastern
A. fergusoni
2b. Background color pale or light brown
Go to 3
3a. Shell whorls rounded; narrow umbilicus
A. jessica
3b. Whorls angled weakly to strongly; umbilicus wider
Go to 4
4a. Color spots small, no radiating streaks
A. strongylodes
4b. Color spots larger, often radiating streaks
A. alternata
Carychium (clappi, exiguum, exile, nannodes)
1a. Shell surface smooth or mostly smooth
Go to 2
1b. Shell ribbed
Go to 3
2a. Shell <1.5 mm tall, thin
C. nannodes
2b. Shell >1.5 mm tall, robust
C. exiguum
3a. Aperture not thickened within; whorls more angular
C. clappi
3b. Aperture thickened within
C. exile
Catinella (avara, hubrichti, oklahomarum, vagans)
1a. Shell plain, pale
C. vermeta
1b. Shell yellowish, amber, or greenish
Go to 2
2a. Forest animal
C. oklahomarum
2b. Shore or marsh animal
Go to 3
3a. Greenish-yellow shell, James City vicinity
C. hubrichti
3b. Yellowish shell, Yorktown vicinity
C. vagans
Cepaea (hortensis, nemoralis)
1a. Shell <22 mm, with light-colored peristome
C. hortensis
1b. Shell >22 mm, usually with brown peristome
C. nemoralis
Cochlicopa (lubrica, lubricella, morseana)
1a. Cylindrical, width/height ratio <0.35
C. morseana
1b. Bulging, width/height ratio >0.35
Go to 2
2a. Wider, usually smaller, often with rosy peristome
C. lubrica
2b. A bit narrower, often larger, plain peristome
C. lubricella
Discus (bryanti, catskillensis, nigrimontanus, patulus, whitneyi)
1a. Shell >7 mm wide
Go to 2
1b. Shell <7 mm wide
Go to 3
2a. Periphery weakly angled, small basal lamella
D. patulus
2b. Periphery strongly angled, no lamellae
D. nigrimontanus
3a. Taller, with rounded whorls
D. whitneyi
3b. Lower, with angled whorls
Go to 4
4a. Carinate (angled) body whorl
D. catskillensis
4b. Bicarinate (two-angled) body whorl
D. bryanti
Euchemotrema (fraternum, leai)
1a. 5+ whorls, densely hirsute
E. fraternum
1b. 6+ whorls, sparsely hairy
E. leai
Euconulus (chersinus, dentatus, fulvus, trochulus)
1a. Final whorl containing 1-3 radial lamellae
E. dentatus
1b. Without lamellae
Go to 2
2a. Shell angular, with pointed apex
E. trochulus
2b. Shells more blunt, beehive-shaped
Go to 3
3a. Final whorl more than half the shell’s height
E. fulvus
3b. Final whorl half or less than shell height, relatively tall, matte finish
E. chersinus
Gastrocopta (armifera, clappi, contracta, corticaria, cristata, holzingeri, pellucida, pentodon, procera, riparia, tappaniana)
1a. Shell >3¼mm tall, cylindrical or barrel-shaped; translucent white when fresh (subgenus Albinula)
Go to 2
1b. Shell <3¼mm tall; ovoid-conical; color white to brown
Go to 3
2a. Columellar lamella with distinct forward and basally pointing lobes, appearing more or less pyramidal in apertural view; shell usually >4 mm tall
G. armifera
2b. Columellar lamella a simple plate, with lower end slightly more deeply inserted into aperture than upper; shell usually <4 mm tall
G. clappi
3a. Angulo-parietal lamella a simple peg-like tooth
Go to 4
3b. Angulo-parietal lamellae not peg-shaped
Go to 6
4a. Fresh shells brown-red
G. cristata
4b. Fresh shells white-transparent
Go to 5
5a. Shell narrowly conical, with height more than 1½ times width; lower palatal lamella deeply entering aperture
G. pentodon
5b. Shell broadly conical, with height less than 1½ times width; lower palatal lamella not deeply entering aperture
G. tappaniana
6a. Angulo-parietal lamella a single large, folded sheet
G. contracta
6b. Angular and parietal lobes of angulo-parietal lamellae distinct
Go to 7
7a. Fresh shells whitish
Go to 8
7b. Fresh shells yellow-brown to brown-red
Go to 9
8a. Basal and palatal lamellae absent; shell >2.4 mm tall
G. corticaria
8b. Basal and palatal lamellae present; shell <2 mm tall
G. holzingeri
9a. Shell tan-yellow; height <2¼ mm tall; apertural margin unthickened
G. pellucida
9b. Shell red-brown; height >2¼ mm tall; apertural margin with thickened callus
Go to 10
10a. Angular lobe of angulo-parietal lamella reduced to a small protuberance
G. cristata
10b. Angulo-parietal lamella distinctly bi-lobed
Go to 11
11a. Lower palatal lamella inserted at roughly the same depth as the upper palatal, positioned approximately at a right angle to the lower aperture margin
G. riparia*
11b. Lower palatal lamella inserted more deeply into aperture than upper palatal, positioned approximately parallel to the lower apertural margin
G. procera
Gastrodonta (fonticula, interna)
1a. Open, well-like umbilicus, height 4 mm or less
G. fonticula
1b. Umbilicus small or closed, height 4 mm or more
G. interna
Glyphyalinia and Nesovitrea (G. carolinensis, cryptomphala, cumberlandiana, indentata, lewisiana, luticola, picea, praecox, raderi, rhoadsi, sculptilis, solida, specus, virginica, wheatleyi; N. electrina)
1a. Shell very small - with 4 whorls, but 4 mm or smaller diameter
Go to 2
1b. Shell medium or large diameter; more than 4 mm diameter
Go to 4
2a. Umbilicus width nearly 1/3 shell diameter
G. raderi
2b. Umbilicus smaller
Go to 3
3a. Umbilicus approximately 1/4 shell diameter
G. cumberlandiana
3b. Umbilicus approximately 1/5 shell diameter
G. lewisiana
4a. Shell large, >6 mm diameter
Go to 5
4b. Shell < 6mm diameter
Go to 9
5a. Shell very large, >10 mm
Go to 6
5b. Shell <10 mm
Go to 7
6a. Widely spaced indented lines, 5.5 whorls maximum
G. carolinensis
6b. Closely-spaced and regular indented lines, up to 7 whorls
G. sculptilis
7a. Umbilicus imperforate
G. solida
7b. Umbilicus perforate, with tiny opening
Go to 8
8a. Shell up to 7.1 mm wide
G. picea
8b. Shell up to 6.3 mm wide
G. praecox
9a. Umbilicus covered, imperforate
G. cryptomphala
9b. Shell perforate or umbilicate
Go to 10
10a. Shell umbilicate
Go to 11
10b. Shell perforate
Go to 14
11a. Umbilicus approximately 1/5-1/6 of shell width
G. rhoadsi
11b. Umbilicus more than 1/5 shell diameter
Go to 12
12a. Shell deep, 2.5-2.8 mm tall
Nesovitrea electrina
12b. Shells < 2.5 mm tall
Go to 13
13a. Slightly larger (5 mm+ diameter)
G. wheatleyi
13b. Slightly smaller (usually <4.5 mm diameter)
G. virginica
14a. Shell slightly deeper (up to 3 mm tall) and with slightly more whorls (4.5-5)
G. indentata
15b. Shell subtly flatter (up to 2.6 mm tall), with fewer whorls (4-4.5)
G. luticola
Hawaiia (alachuana, minuscula)
1a. Cross-hatched microsculpture, lip of aperture meets penultimate whorl close to umbilicus; diameter approximately 3.5x the umbilical width
H. minuscula
1b. Primarily radial microsculpture, lip of aperture meets penultimate whorl away from midline; diameter approximately 2.5x the umbilical width
H. alachuana
Helicodiscus (diadema, fimbriatus, hadenoecus, lirellus, multidens, notius, parallelus, shimeki, triodus)
1a. Shell with palatal, basal, and parietal lamellae in final whorl
Go to 2
1b. Shell with palatal and basal lamellae only (no parietal lamellae), or with no lamellae
Go to 5
2a. Shell with one or more sets of basal and palatal teeth joined into a single notched lamella, radially flattened; flange-like parietal tooth
H. multidens
2b. Shell with one or more sets of distinct basal and palatal teeth, flange-like parietal tooth
Go to 3
3a. Basal and palatal teeth distinct, but flattened radially – flange-like
H. lirellus
3b. Basal and palatal teeth distinct, rounded or cone-shaped
Go to 4
4a. Shell with “hairs” adorning the lirae, though they may be sparse or mostly worn off
H. diadema
4b. Shell without hairs
H. triodus
5a. Shell with distinctly fringed lirae, which may be worn off, flat apex and shallow umbilicus, no teeth visible in aperture
H. fimbriatus
5b. Shell with lirae but no distinct fringes, teeth may or may not be visible in aperture
Go to 6
6a. Shell small (<3 mm), with spiral lirae and radial ridges, interrupted at intervals by growth ridges; may be nearly smooth except on base; without teeth in final whorl
H. hadenoecus
6b. Shell larger, with distinct spiral lirae
Go to 7
7a. Shell with flat apex, shallow umbilicus
H. shimeki
7b. Shell with slightly raised apex, deeper umbilicus
Go to 8
8a. Spiral striae on embryonic whorl distinct
H. notius (of questionable validity)
8b. Spiral striae on embryonic whorl weak
H. parallelus
Inflectarius (inflectus, kalmianus, rugeli)
1a. Shell globe-shaped, lacking teeth in aperture
I. kalmianus
1b. Shell somewhat depressed, with three teeth in aperture
Go to 2
2a. Shell smaller (9.5-12 mm wide), basal tooth visible in side view
I. inflectus
2b. Shell larger (11-15 mm wide), basal tooth not visible in side view, though seen from below
I. rugeli
Lucilla (scintilla, singleyana)
1a. Shell clear or whitish, up to 3 mm wide, flat spire
L. singleyana
1b. Shell yellowish, <2.5 mm wide, slightly raised spire
L. scintilla
Mesodon and Neohelix (M. andrewsae, clausus, elevatus, mitchellianus, normalis, thyroidus, zaletus; N. albolabris, major, solemi, dentifera)
1a. Shell bearing a parietal tooth
Go to 2
1b. Shell without a parietal tooth
Go to 5
2a. Umbilicus narrowly open, slit-like
M. thyroidus
2b. Umbilicus closed
Go to 3
3a. Aperture with low, ridge-like basal lamella
M. elevatus
3b. Aperture without basal lamella
Go to 4
4a. Shell very depressed, low spire
N. dentifera
4b. Shell slightly depressed
M. zaletus
5a. Umbilicus narrowly open
M. clausus (probably M. thyroidus)
5b. Umbilicus closed
Go to 6
6a. Shell <20 mm wide
M. mitchellianus
6b. Shell >20 mm wide
Go to 7
7a. Shell with a wide, low basal lamella, close to the columella; western
M. normalis
7b. Shell without a low basal lamella
Go to 8
8a. Shell very thin, found above 2,000’ elevation
M. andrewsae
8b. Shell robust
Go to 9
9a. Shell >28 mm (some overlap with below); only found central-to-west
N. major
9b. Shell <32 mm (some overlap); found statewide
Go to 10
10a. Relatively narrow lip (basal lip average width <0.65 mm); found on the Coastal Plain
N. solemi
10b. Average lip (basal lip width average >0.65 mm); widespread
N. albolabris
Mesomphix (capnodes, cupreus, inornatus, perlaevis, rugeli, subplanus)
1a. Microsculpture of body whorl has spiral and radial striae that create a pattern of tiny papillae
Go to 2
1b. No pattern of papillae
Go to 4
2a. Shell diameter 28 mm or more
M. capnodes
2b. Shell diameter <28 mm
Go to 3
3a. Papillae in dense, neat, rows and columns; shell lower
M. inornatus
3b. Papillae weak in most places; shell taller
M. perlaevis
4a. Umbilicus small, but obvious; shell often with dark brown peristome
M. cupreus
4b. Umbilicus tiny, perforate; shell lip plain
Go to 5
5a. Shell quite flattened
M. subplanus
5b. Shell moderately or strongly domed
Go to 6
6a. Shell moderately domed; spiral striae across the top of growth ridges
M. perlaevis
6b. Shell very domed; lacking spiral striae
M. rugeli
Novisuccinea and Succinea (N. ovalis; S. campestris, wilsonii)
1a. Found in woods, especially in stream valleys
N. ovalis
1b. Found on coastal dunes, marshes, tidewater
Go to 2
2a. Shell quite rounded, light-colored; dunes and shoreline
S. campestris
2b. Apex variable in height, shell usually yellow; brackish water, marshes
S. wilsonii
Oxychilus (cellarius, draparnaudi)
1a. Shell smaller, <4 mm tall
O. cellarius
1b. Shell larger, >4 mm tall
O. draparnaudi
Oxyloma (effusum, retusum, subeffusum)
1a. Shell aperture approximately 2/3 the total shell length
O. retusum
1b. Shell aperture larger than 2/3 total shell length
Go to 2
2a. Shell aperture approximately 3/4 total shell length
O. subeffusum
2b. Shell aperture 4/5 total shell length
O. effusum
Paravitrea (blarina, capsella, dentilla, hera, mira, lamellidens, multidentata, placentula, pontis, reesei, septadens, seradens, subtilis, tridens)
1a. Shell width 5 mm or less
Go to 2
1b. Shell width >5 mm
Go to 7
2a. Teeth or lamellae absent
P. blarina
2b. Teeth present (though may be deeply recessed)
Go to 3
3a. Shell 3.5 mm wide or more
Go to 4
3b. Shell <3.5 mm wide
Go to 5
4a. Shell with lunate aperture; 1-3 curved radial lamellae
P. lamellidens
4b. Shell with deeply-recessed basal teeth in final whorl; aperture somewhat triangular, widest at base
P. reesei
5a. Shell with 1-2 simple radial lamellae in final whorl
P. septadens
5b. Shell with rows of teeth in final whorl
Go to 6
6a. Shell with radial but curved rows of several small teeth in final whorl
P. multidentata
6b. Final whorl with Radial rows of teeth, but not angled or curved
P. subtilis
7a. Shell diameter 5-6.5 mm
Go to 8
7b. Diameter >6.5 mm
Go to 12
8a. No teeth in adult shells
Go to 9
8b. Teeth or lamellae in adult shells
Go to 11
9a. Shell a depressed dome with umbilicus showing preceding 1.5+ whorls. Umbilicus approximately 20% of shell width
P. pontis
9b. Shell a taller dome with a well-like umbilicus approximately 15% of shell diameter
Go to 10
10a. Shell widespread. Immatures with radial pairs of teeth
P. capsella
10b. Shell not reported in Virginia, but may occur in the far west. Immatures with radial sets of three teeth
P. tridens
11a. Shell 5.5 mm; low dome 2.8 mm
P. seradens
11b. Shell 6.3 mm; taller dome 3.9 mm
P. mira
12a. Umbilicus approximately 1 mm wide
P. hera
12b. Umbilicus >1 mm wide
Go to 13
13a. Juveniles with sets of paired teeth; shell up to 7.5 mm wide
P. placentula
13b. Juveniles with sets of 5-6 teeth; shell up to 7 mm wide
P. dentilla
Patera (appressa, laevior, panselenus)
1a. Shell bears scattered sparse, tiny papillae in spiral pattern
P. appressa
1b. No papillae
Go to 2
2a. Shell sculpture includes deeply incised spiral lines; usually >18 mm diameter
P. panselenus
2b. Weak spiral striae; usually <18 mm diameter
P. laevior
Pomatiopsis (cincinnatiensis, lapidaria)
1a. Shell usually <5 mm long; narrower
P. cincinnatiensis
1b. Shell usually >5 mm long; stouter
P. lapidaria
Punctum (blandianum, minutissimum, smithi, vitreum)
1a. Aperture with small basal tooth
P. smithi
1b. No teeth
Go to 2
2a. Umbilicus wider, shell width <3x umbilicus width
P. blandianum
2b. Umbilicus narrower, shell width >3x umbilicus width
Go to 3
3a. Larger ribs widely spaced with cross-hatch pattern between
P. vitreum
3b. No cross-hatch pattern; ribs all of similar size
P. minutissimum
Stenotrema (altispira, barbatum, burringtoni, edvardsi, hirsutum, macgregori, pilula, spinosum, stenotrema)
1a. Shell angular or lens-like
Go to 2
1b. Shell rounded, depressed globe shape
Go to 3
2a. Edge of final whorl very angular or carinate; no “hairs”; shell >10 mm diameter
S. spinosum
2b. Edge of final whorl angular; “hairy” above; shell <10 mm diameter
S. edvardsi
3a. Shell very small, <6.5 mm diameter; southern edge of Virginia, if at all
S. pilula
3b. Shell >6.5 mm diameter
Go to 4
4a. Interdenticular sinus indistinct
Go to 5
4b. Interdenticular sinus pronounced
Go to 6
5a. Apex low, shell deep
S. barbatum
5b. Apex domed
S. macgregori
6a. Shell smaller, up to 9.5 mm diameter; widest part of body whorl above equator
Go to 7
6b. Shell larger, up to 11 mm diameter; widest part of body whorl at or below the equator
Go to 8
7a. Shell with sinuous parietal lamella, deeply inserted in interdenticular sinus; deeply notched basal lip with a small tooth on the right side
S. burringtoni
7b. Shell with nearly horizontal parietal lamella, shallow interdenticular sinus; shallow notch in basal lip, no tooth to the right side
S. hirsutum
8a. Parietal lamella large, in side view extends to edge of shell, obscuring aperture
S. stenotrema
8b. Parietal lamella smaller, does not obscure entire aperture
S. altispira
Striatura (exigua, ferrea, meridionalis, milium)
1a. Shell diameter >2 mm
Go to 2
1b. Shell diameter <2 mm
Go to 3
2a. Shell covered with fine spiral and radial lines, silky texture
S. ferrea
2b. Shell with transverse ridges, between the ridges are wavy spiral lines crossed by radial lirae
S exigua
3a. Embryonic whorls smooth
S. milium
3b. Embryonic whorls sculptured with spiral lirae
S. meridionalis
Strobilops (aeneus, labyrinthicus, texasianus)
1a. Angular periphery of the body whorl
S. aeneus
1b. Rounded periphery
Go to 2
2a. Ribs extending strongly onto the underside
S. texasianus
2b. Ribs above become faint below the periphery
S. labyrinthicus
Triodopsis (alabamensis, anteridon, burchi, fallax, fraudulenta, hopetonensis, juxtidens, messana, obsoleta, pendula, picea, tennesseensis, tridentata, vulgata)
1a. Pointed or small palatal tooth
Go to 2
1b. Wide or blunt palatal tooth
Go to 7
2a. Palatal tooth very small, weak
Go to 3
2b. Palatal tooth pronounced
Go to 5
3a. Shell diameter >18 mm
T. tennesseensis
3b. Shell diameter <18 mm
Go to 4
4a. Parietal tooth pointing at or below the palatal tooth; basal tooth nearly obsolete, upon a wide buttress
T. burchi
4b. Parietal tooth pointing above the palatal tooth; basal tooth small and pointed
T. obsoleta
5a. Palatal tooth a small point upon the dorsal end of a broader buttress
T. pendula
5b. Parietal tooth not upon a buttress
Go to 6
6a. Parietal tooth points below the palatal tooth
T. tridentata
6b. Parietal tooth points at or above the palatal tooth
T. juxtidens
7a. Palatal tooth not bent inward
Go to 8
7b. Palatal tooth bent strongly inward, or recessed, or upon a dished peristome
Go to 10
8a. Basal tooth small, upon a wide peristome
T. picea
8b. Basal tooth upon the distal end of a buttress
Go to 9
9a. Aperture crowded, narrow space between large parietal and basal teeth
T. fallax
9b. Aperture more open, teeth smaller
T. pendula
10a. Shell large, >14 mm diameter
T. fraudulenta
10b. Shell <14 mm diameter
Go to 11
11a. Lower margin of peristome rounded
Go to 12
11b. Lower margin of peristome flat
Go to 13
12a. Parietal tooth continuous with peristome; shell smaller, up to 14 mm diameter
T. messana
12b. Parietal tooth not connected by a callus to the peristome; shell larger, up to 15 mm diameter
T. vulgata
13a. Parietal tooth larger, connected to peristome by a callus
T. alabamensis
13b. Parietal tooth small and straight, not continuous with peristome
T. hopetonensis
Vallonia (costata, excentrica, parvula, perspectiva, pulchella)
1a. Shell with growth ridges but not prominent ribs
Go to 2
1b. Prominent, widely-spaced ribs
Go to 3
2a. Umbilicus round; lip expanded at exterior margin
V. pulchella
2b. Umbilicus more oval-shaped; lip widens but not rapidly expanded to exterior (is reflected within the aperture)
V. excentrica
3a. Peristome narrowly reflected, continuous upon body whorl of shell
V. perspectiva
3b. Peristome widely reflected, not continuous upon body whorl
Go to 4
4a. Shell diameter 2 mm or less
V. costata
4b. Shell diameter >2 mm
V. parvula
Ventridens (acerra, arcellus, cerinoideus, coelaxis, collisella, decussatus, demissus, gularis, intertextus, lasmodon, lawae, ligera, pilsbryi, suppressus, theloides, virginicus)
1a. No lamellae within aperture (though there may be a callus)
Go to 2
1b. One or more lamellae within aperture
Go to 8
2a. Shell >10 mm diameter
Go to 3
2b. Shell <10 mm diameter
Go to 6
3a. Shell texture fine, but not glossy; often with subtle spiral line on the outside of the final whorl
V. intertextus
3b. Shell smooth, glossy
Go to 4
4a. Umbilicus narrow but well-like
V. arcellus
4b. Umbilicus very narrow, perforate
Go to 5
5a. Base of shell rounded, not as glossy
V. ligera
5b. Base flattened, shell very glossy
V. acerra
6a. Umbilicus perforate
V. demissus
6b. Umbilicus nearly covered by the expanded edge of the lip
Go to 7
7a. Basal edge of lip not deflected; Coastal Plain animal; live animal dark-colored
V. cerinoideus
7b. Basal edge of lip deflected; inland forest dweller; live animal pale
V. theloides
8a. Shell small, <7 mm diameter
Go to 9
8b. Shell >7 mm diameter
Go to 11
9a. Umbilicus >0.4 mm
V. coelaxis
9b. Umbilicus <0.4 mm
Go to 10
10a. Columellar lamella bilobed
V. virginicus
10b. Columellar lamella singular
V. suppressus
11a. Usually with two lamellae
Go to 12
11b. Often with a single lamella and a columellar callus
Go to 15
12a. Very wide umbilicus, approximately 1/3 of shell diameter
V. lasmodon
12b. Umbilicus smaller
Go to 13
13a. Small but open umbilicus; spiral lines crossing radial striae on outer half of base
V. decussatus
13b. Perforate or rimate umbilicus
Go to 14
14a. Weak, rounded striae on upper shell surface
V. pilsbryi
14b. Distinct striae on upper shell
V. gularis
15a. Deep, well-like umbilicus
V. lawae
15b. Umbilicus tiny, perforate
V. collisella
Vertigo (alabamensis*, bollesiana*, clappi, cristata*, elatior*, gouldii, malleata*, milium, oralis, oscariana, ovata, parvula, pygmaea, teskeyae, tridentata, ventricosa)
*not yet reported for Virginia
1a. Body whorl strongly pustulose
V. malleata*
1b. Body whorl lacking strong pustulose bumps
Go to 2
2a. Upper palatal lamella long, tall and longitudinally curved, allowing long axis to be visible in apertural view
Go to 3
2b. Upper palatal lamella short, low and straight, with long axis barely visible in apertural view
Go to 4
3a. Aperture margin thickened; shell color deep yellow; imperforate
V. alabamensis*
3b. Aperture margin not thickened; shell color light yellow to horn; narrowly umbilicate
V. clappi
4a. Shell surface smooth or weakly striate
Go to 5
4b. Shell surface strongly striate
Go to 19
5a. Five or fewer apertural lamellae
Go to 6
5b. Six or more apertural lamellae
Go to 7
6a. Four or fewer apertural lamellae
Go to 11
6b. Five apertural lamellae
Go to 15
7a. Shell surface dull
Go to 8
7b. Shell surface shiny
Go to 9
8a. Angular lamella absent; weak or absent sinulus; callus on palatal wall light-colored; shell surface with satin luster
V. pygmaea
8b. Angular lamella present; strong sinulus; callus on palatal same color as rest of shell; shell surface striate and with faint spiral lines
V. oralis
9a. Shell <1.9 mm tall; ovate; lower palatal lamella long, curved and deeply entering shell
V. milium
9b. Shell >2.0 mm tall; basally obese; lower palatal lamella short and not deeply entering shell
Go to 10
10a. Aperture wider than tall; columellar lip of aperture broad, more or less straight and angled away from palatal wall; shallow suture
V. teskeyae
10b. Aperture as tall as wide; columellar lip of aperture rounded, and curved towards palatal wall; deeper suture
V. ovata
11a. Body whorl narrower than penultimate whorl, making shell bluntly conical at both top and bottom; columellar lamella elongate and vertical
V. oscariana
11b. Body whorl at least as wide as the penultimate whorl; columellar lamella peg-shaped
Go to 12
12a. Body whorl inflated, making shell height less than twice the width
Go to 13
12b. Body whorl not greatly inflated, making shell height approximately twice the width
Go to 14
13a. Shell height >2 mm; strong apertural lamellae and sinulus
V. ovata
13b. Shell height < 2 mm; moderate apertural lamellae and sinulus
V. ventricosa*
14a. Shell height >1¾ mm; a weak upper palatal lamella often present
V. tridentata
14b. Shell height <1¾ mm; upper palatal lamella always absent
V. parvula
15a. Shell height less than twice the width, with marked basal inflation
Go to 16
15b. Shell height twice the width or more, ovoid
Go to 17
16a. Shell height >2 mm; strong apertural lamellae and sinulus
V. ovata
16b. Shell height < 2 mm; moderate apertural lamellae and sinulus
V. ventricosa*
17a. Shell weakly striate; single deep depression behind aperture over palatal lamellae
V. bollesiana*
17b.Shell smooth; separate slight depressions under each palatal lamellae, or none
Go to 18
18a. Shell surface dull; strong crest; light-colored callus on palatal wall
V. pygmaea
18b. Shell surface shiny; crest less prominent; callus of same color as shell
V. elatior*
19a. Four apertural lamellae
V. cristata*
19b. More than four apertural lamellae
Go to 20
20a. Six apertural lamellae
V. oralis
20b. Five apertural lamellae
Go to 21
21a. Striae indistinct, with shell often appearing smooth under low (x10) magnification; single deep depression over both palatal lamellae; ~1¾ mm tall
V. bollesiana*
21b. Striae distinct, with shell not appearing smooth under low (x10) magnification; palatal depression weak or absent; most forms >1¾ mm tall, with small southern Appalachian forms being ~1¾ mm
V. gouldii
Zonitoides (arboreus, elliotti)
1a. Shell >7 mm diameter; basal lip slightly reflected
Z. elliottii
1b. Shell <7 mm diameter; lip simple
Z. arboreus