670 



PROCEEDINGS OF THE ACADEMY OF 



[Dec, 



Alt. 3.03, diam. .92 mm. 



Locality. — Bermuda; collected by W. M. Rankin. Type in the 

 collection of the Acad. Nat. Sci. Phila., No. 82,410. 



This shell differs from P. exacutus Say by the smaller size, the 

 position of the keel at the periphery instead of near the base, the 



Fig. 3. — Planorbis imus n. sp. 



more vertical aperture and shallower umbilicus. It is more depressed 

 than P. alabamensis Pils. and P. dilatatus Gld. The aperture is not so 

 oblique in P. rubcUus St., has a more rapid increase of whorl, narrower 

 umbilicus and lighter color. 



Ancylus (Ferrissia) bermudensis n. sp. Fig. 4. 



Shell oval, greatest width in front, high, thin, horn color, apex with 

 microscopic radial striae, situated near the posterior right margin, 

 anterior slope convex, posterior and right side concave, left side 



Fig. 4. — Ancylus bermudensis n. sp. 



nearly straight. Surface marked with concentric lines of growth and 

 a few obscure radial lines. 



Alt, .90, diam. 1.73, length 3.10. 



Locality. — Ditch in Pembroke Marsh, near Hamilton, Bermuda. 



This rare limpet is smaller and smoother than A. radiatus Guild, and 

 A. textilis Guppy. A. irroratus Guild, has stronger concentric sculpture. 



