Tight-Gapped Shagreen

(G. H. Clapp, 1905)

Inflectarius approximans







Taxonomic Information

Polygyra inflecta approximans

Original Combination:

approximans = approaching [latin], refering to the close approximation of the lip teeth


Original Description:

Differs from typical inflecta in the closely appoximated lip teeth, the space between them measuring only about 1/2 mm. in width, while in the typical form it measures 1 mm. and over. The aperture is also wider in proportion to its length, and less rounded in front; body-whorl narrower at the aperture, not swollen back of the lip. In other characters like the type- whorls about 4 1/2. A considerable proportion of the shells have the umbilicus partly open, and while this can hardly be considered a specific character the proportion is greater than in any lot of infecta I have seen.
Greater diam. 7 1/2, lesser 1/2, alt. 4 1/2 mm.
Greater diam. 8, lesser 7, alt. 5 mm.
Greater diam. 8 1/2, lesser 7 1/2, alt. 4 3/4 mm.
Greater diam 8 3/4, lesser 7 3/4, alt. 5 mm.
Marion, Ala., where it practically replaces the typical form as only four dead shells of the latter were found. Collected by Herbert H. Smith in May, 1905. A specimen of P. inflecta from Jackson, Ala., is figured for comparison, pl. 3, fig. 5. Types No. 5389 of my collection and cotypes in the collections of the Academy of Natural Sciences, Bryant Walker and T.H. Aldrich.

Original Description Citation:

Clapp, G. H. (1905). Description of two new forms of Polygyra. The Nautilus. 19(7): 73-74, plate 3., available online at https://www.biodiversitylibrary.org/page/1755573 page(s): 74, pl. 3, fig. 6

Ecological Information



Nature Serve Conservation Status:

G2: Imperiled