Fringed Slitmouth

(Redfield, 1856)

Stenotrema barbigerum

Class:

Order:

Family:

Gastropoda

Stylommatophora

Polygyridae

Taxonomic Information

Helix barbigera

Original Combination:

barbigera = bearded man [latin]

Etymology

Original Description:

Shell imperforate, sharply carinate, rather thin, dark horncolored, or brown; the upper surface has the epidermis raised into acute striae, which, at the suture and carina, are produced into short bristles; these epidermal striae are sometimes seen beneath, but less distinctly, being often obsolete in the mature shell; basal surface convex, but indented in the umbilical region; spire slightly convex, whorls five and a half, rather flat, last one suddenly but slightly deflected; aperture very oblique, transverse, ear-shaped, narrowed by a rather slender tongue-shaped tooth, which extends neraly across the whole width of the aperture; peristome callous, margins slightly but distinctly reflected, and thickened within, basal margin slightly arcuate, but entire.
Diam. maj. 10 mill. Diam. min. 9 mill. Alt. 6 mill.
Habitat.-Habersham Co., Georgia, where it was collected by Bishop Elliott.
Observations.-Closely allied to H. spinosa Lea, and H. Edgariana Lea; but a careful examination of many individuals of the three types led me to concur in the conclusions previosly arrived at by Mr. Bland and Mr. Binner, that the three forms are specifically distinct. In size the H. barbigera resembles H. Edgariana, but is readily distinguished by its much more slender parietal tooth, and by the absence of the notch in peristome. The notch is usually present in H. spinosa, but that species, like H. Edgariana, has the parietal tooth elongated and very strongly developed. Moreover, H. barbigera is much smaller than H. spinosa (being only about two-thirds its diameter), and has about half a whorl less. The epidermidal striae are more numerous, more sharply raised, and as a consequence the cilia are more numerous than in H. spinosa. In the latter the lower lip rises from a deep excavation in the umbilical region, and the parietal tooth is partially curved round the excavation, somewhat overlapping the lower lip at its junction with the columella. This peculiarity is most distinct in the large form of H. spinosa from Alabama, less so in the smaller form from Tennessee. In H. barbigera the base is less excavated, and the lower lop and tooth are more allied to H. fraterna Say than to H. spinosa. The lip is distinctly reflected, not merely appressed, as in H. spinosa.
The three forms, H. barbigera, H. spinosa, and H. Edgariana bear to each other relations somewhat analogous to those which connect H. fraterna Say, H. hirusta Say, and H. maxillata Gould.

Original Description Citation:

Redfield, J.H. (1856). Descriptions of two new species of North American Helicidae. Annals of the Lyceum of Natural History of New York, 6: 170-172.

Ecological Information

Native/Inavsive:

Native

Nature Serve Conservation Status:

G3: Vulnerable

Diet

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Citations

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