Superfamily Arionoidea Family DiscidaeDiscus rotundatus(Müller,1774)Rounded snail Shell pale yellowish brown with red-brown stripes,5 mm wide x 7 mm high,with 5,5-6,5 whorls. In sheltered shaded places,gardens. West-and Central-Europe,in Switzerland up to 2700 mtrs.
Anquispira alternata Say,1816 Shell pale yellow with irregular markings and spots,depressed with strong rounded axial ribs,umbilicus large and lip thin. Diameter is 15-30 mm,height is 9-17,5 mm. The animal is bright in color and leaves an orange trail. In Canada to Georgia and west to South-Dakota and Kansas. A sub-species with a heavy shell and strong ribs is called A.a.crassa(Walker). It is found in Virginia to Florida.
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Anguispira nimapuna Baker,1932
© 2002 William Leonard
Discus cronkhitei(Newcomb) Shell flat with fine axial ribs,brown,5.7 mm in diameter and 3 mm in height. The umbilicus is large and the lip hin. In fields and forestedges,also in urban areas. In Canada and Maine to Maryland and west to the West-Coast. The subspecies D. c. catskillensis(Pilsbry) has an obtuse keel and is found in Canada to Pennsylvania and west to Minnesota.
Discus palulus(Deshayes) Shell 8-9 mm in diameter,ribs coarse and widely separated,umbilicus very large. In Canada to western Florida and west to Iowa and Arkansas.
Anguispira kochi(Pfeiffer,1845) Shell:helicoid,dark brown with 2 spiral bands,6 whorls,about 25 mm wide The umbilicus is medium-sized.The animal is pale brownish or brownish cream with dark tentacles. Habitat:in moist wooded areas,often along lakes and streams. Area:North-America and Canada
image copyright Robert Forsyth
Discus whitneyi(Newcomb,1864) Shell:flat helicoid,brown transparent with 4,5 whorls,the suture is deep and the umbilicus large,small ribs.About 6,5 mm wide. Habitat:in wooded areas under logs,leaf litter and rocks.It has been found at 3000 mtrs altitude. Area:North-America.
image copyright Robert Forsyth
Discus shimekii(Pilsbry,1890) Shell:flat helicoid,yellowish brown,with small ribs,the umbilicus is large. About 6,5 mm wide. Habitat:under rocks and dead wood,often on mountains. Area:North-America,Canada(New-Mexico,Arizona,British-Columbia)
image copyright Robert Forsyth