Monte Sano Slitmouth

(G. H. Clapp, 1905)

Stenotrema deceptum







Taxonomic Information

Polygyra decepta

Original Combination:


Original Description:

By comparison with hirsuta the following differences will be noted: Lip broader and more rounded at the top so that when the shell is viewed from below, the body-whorl joins it in a regular curve instead of forming an obtuse angle; parietal tooth hooked at the outer end and curving into the aperture, the lip being deeply recessed around it; lip-notch narrow and sinuous with a well raised margin which projects above the level of the pariental tooth; width of aperture, measured from back of lip to edge of parietal callus across the lip-notch, more than half the length, while in hirsuta it is less; parietal tooth not quite joining lip at basal margin; internal tubercle short and completely covered by the lip so that it is not visible through the base of the shell. The parietal tooth is connected to the base of the lip by a slight buttress and there is a well developed tooth-like proccess on the lip, but these characters are common to most of the species of this group. Color and hairs about the same as in hirsuta.
The outline figures bring out the differences better than the description, decepta being drawn from the type and hirsuta from Blount Springs shell.
Type: Greater diam. 7, lesser 6 1/2, alt. 4 3/4 mm., whorls 5.
Greater diam. 6 1/4, lesser 5 3/4, alt. 4 1/2 mm. whorls 4 2/3.
These measurements show the extreme variation in size.

Original Description Citation:

Ecological Information



Nature Serve Conservation Status:

G3: Vulnerable