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''Amnicola walkeri'', common name Canadian duskysnail, is a species of freshwater snail, an aquatic gastropod mollusk in the family Amnicolidae. The name is in honor of Mr. Bryant Walker.〔 == Shell description == The shell is thin, narrowly umbilicate, conic, shaped like ''Lyogyrus brownii'' Carpenter. The color of the shell is slightly yellowish corneous. The shell is thin, smooth, with faint growth-lines. The shell has 4 whorls that are very convex and separated by deeply constricting sutures. The last whorl is rounded below. The apex is obtuse.〔 The aperture is oblique, rather small, mainly basal, a little longer than wide, but nearly circular. The inner margin is a trifle straightened above. The peristome is continuous, in contact with the preceding whorl for an extremely short distance above. Operculum is amnicoloid.〔 The width of the shell is 2-2.125 mm. The height of the shell is 2.33–3 mm. The width of aperture is 1-1.125 mm. The height of aperture is 1.08-1.25 mm.〔 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「Amnicola walkeri」の詳細全文を読む スポンサード リンク
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