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''Stagnicola utahensis'', common name the thickshell pondsnail, is a species of air-breathing freshwater snail, an aquatic pulmonate gastropod mollusk in the family Lymnaeidae, the pond snails. This species is endemic to Utah in the USA. The last living snails were found in the 1930s. == Shell description == The shell is globose, somewhat umbilicated and irregularly costate. The color of the shell is light horn and nearly pellucid. The spire is rather small and conical. The shell has from 4 to 4 and half convex whorls, that are somewhat flattened above, giving rather a shouldered appearance to the whorls. Whorls are rapidly increasing in size. The last whorl is inflated, with numerous rather marked transverse costae and minutely wrinkled. The suture is somewhat deep, regularly impressed.〔 The aperture is elongately ovate, effuse, approaching patulous and pearly white within. The outer lip is simple and its margin is connected by a slight calcareous deposit. The columella is somewhat twisted, but straight in front.〔 The average width of the shell of ''Stagnicola utahensis'' is 7.10 mm. The average height of the shell is 13.40 mm. The maximum width of the shell is 8.88 mm. The height of the shell is 16.82 mm. The width of the aperture is 5.90 mm. The height of the aperure is 9.00 mm.〔 File:Stagnicola utahensis shell 2.jpg|Drawing of apical view of the shell File:Stagnicola utahensis shell 3.jpg|Drawing of lateral view of the shell 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Thickshell pondsnail」の詳細全文を読む スポンサード リンク
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