Group G Key

Group G. Wider than tall; simple lip

This is a diverse group of snails of all sizes, 16 genera - from the smallest species to among the largest. Their uniting character is their simple unreflected lip.

G1. Heliciform, simple lip, globose to subglobose, umbilicus varies, no teeth, >5-30 mm - Anguispira, Haplotrema, and Mesomphix

G2. Heliciform, simple lip, subglobose to depressed, umbilicate to perforate, > 3-4 mm - Discus, Glyphyalinia, Oxychilus, and Zonitoides

G3. Heliciform, simple lip, subglobose to depressed, umbilicate to perforate, < 3 mm – Guppya, Hawaiia, Lucilla, Nesovitrea, Punctum, and Striatura

G4. Heliciform, simple lip, subglobose to depressed, perforate, internal teeth, 2-10 mm – Gastrodonta, Helicodiscus, and Paravitrea

G1. Heliciform, simple lip, globose to very subglobose, umbilicus varies, no teeth, >5-30 mm - Anguispira, Haplotrema, Mesomphix

Tigersnails (Anguispira) - The shell coloration is readily identifiabl, even injuvenile specimens which tend to hae a more angular body whorl. Two species in Indiana.

Go to the Anguispira Page.

Lancetooth snails (Haplotrema) - only one in the state. Very subglobose, almost depressed except for the retained curvaure of the upper shell. The umbilicus spires out widely from a pinhole start.

Go to the Haplotrema Page.

Button snails (Mesomphix) are large woodland snails. Their aperture, like a slanted wide-mouth frog, is an important character. The whorls, see from above spiral out in successively wider spacing.

Go to the Mesomphix Page.

G2. Heliciform, simple lip, subglobose to depressed, umbilicate to perforate, 3-12 mm - Discus, Glyphyalinia, Oxychilus, Zonitoides

Disc Snails (Discus) are small snails with a wide and deep umbilicus and prominent radial ridges.

Go to the Discus Page.

Glyph Snails (Glyphyalinia) are small to mid-sized snails with a perforate umbilicus, radial lines across the whorls, and quickly expanding whorls. The aperture opening is slightly lunate.

Go to the Glyphyalinia Page.


see image of Glass Snails

Glass snails (Oxychilus) are an introduced species from Europe.

Go to the Oxychilus Page.

Gloss Snails (Zonitoides) are small snails with noticeable growth wrinkles. Their whorls grow more regularly that those of the Glyph and Glass Snails.

Go to the Zonitoides Page.

G3. Heliciform, simple lip, subglobose to depressed, umbilicate to perforate, < 5 mm – Guppya, Hawaiia, Lucilla, Nesovitrea, Punctum, Striatura

These are among the smallest of land snail species with the general shape as you hold them in your hand. Magnification is important for identification. This is an attempt to use a key to distinguish the genera:

Small Round Snail Keylet

1a. Shell 3-5 mm in diameter – go to 2
1b. Shell <3 mm in diameter – go to 3

2a. 4-5 mm in diameter; depressed shell; glossy with clear radial lines; about rapidly enlarging whorls; umbilicus wide; looks superficially like Zonitoides arboreus.- Go to Nesovitrea below
2b. about 3-4 mm in diameter, coiled shape like Helicodiscus but lacks spiral ridges; wide umbilicus, 5-5 ½ whorls, flat spire (perhaps a slight elevation) – Go to 3

3a. Shell 2-2.8 mm in diameter; without ribs or riblets - Go to 4
3b. Shell less than 2 mm in diameter; riblets low and closely spaced - Go to 5

4a. Shell less depressed, wider and shallower umbilicus – Go to Hawaiia below
4b. Shell more depressed to discoidal, umbilicus not so wide – Go to Lucilla below

5a. Shell 1.5 mm or less in diameter; initial 1 ½ whorls smooth, 3.5-4.5 whorls – Go to Punctum below
5b. Shell between 1.5-3.0 mm in diameter - Go to Striatura below

Granule Snails (Guppya) are among the smallest of land snails only 1.2-1.3 mm in diameter with 3.5-4 whorls.

Go to the Guppya Page.

Gem Snails (Hawaiia) are tiny (~ 2.2 mm diameter), as is the rest of this group of heliciform snails. They have a wide, shallow umbilicus. The nuclear whorl is smooth but the rest of the surface is cross-hatched with fine, irregularly-spaced growth lines and minute spiral striae

Go to the Hawaiia Page.

Coil Snails (Lucilla) are depressed heliciform, simple lip, umbilicate, ~ 2-2.5 mm. They lack spiral threads as found in the genus Helicodiscus.

Go to the Lucilla Page.

Glass Snails (Nesovitrea) have radial lines much like Glyph Snails but have a small open umbilicus. The aperture opening is more round.

Go to the Nesovitrea Page.

Spot Snails (Punctum) are among the tiniest of and snails.

Go to the Punctum Page.

Striate Snails (Striatura) are small but ornate snails with notable ribs.

Go to the Striatura Page.

G4. Heliciform, simple lip, subglobose to depressed, perforate, internal teeth, 2-10 mm – Gastrodonta, Helicodiscus, Paravitrea

Coil Snails (Helicodiscus) are small snails (< 4 mm) with a discoidal "cinnamon roll" shape. and distinct multiple spiral ridges.

Go to the Helicodiscus Page.

Bellytooth Snails (Gastrodonta) are heliciform snails with a simple lip, a subglobose to domelike shell, perforate, 6-8 mm diamter; over 8 whorls, 2 teeth seen in aperture and others inside that can be seen through the shell..

Go to the Gastrodonta Page.

Supercoil Snails (Paravitrea) are .heliciform snails with many very tightly coiled whorls - a key trait for comparison. They also have a shallow dome-like shell, but the whorls separate them from other species with domed shells.

Go to the Paravitrea Page.