no 



This species, like the galta, is often found coated over with the 

 oordcal envelope of the Gorgonia, and the animal destroyed, pro- 

 bably by its encroaehinent. 



CoROxrLA DEMrLATA. — SheU depTessed-conic; base oval: 

 height equal to about one-third of the base ; valves and interstice-- 

 smooth, the anterior valve largest, and the posterior one smallest ; 

 operctdum transversely striated, the p>Osterior pair of valves with :* 

 submaiginal impressed line, from ^hich to the edge are drawn 

 three or four other impressed lines. 



Found on the clypeus of Limuhis Polyphemus. CoUeetion o: 

 the Academy and Philadelphia Museum. 



The posterior margins of the posterior valves of the operculum, 

 are divided by the impressed lines into three or four broad, flat. 

 dentiform divisions, which, however, but simply crenate the edge 



[J. A. N. S. Vol. ii. p. 378, et seqq. Dec. 1S22.] 



LriiXTTS HUjniJS. — Shell ovate-conic, thin, translucent, with 

 slight wrinkles ; volutions nearly sis, convex, terminal one very 

 minute ; suture well indented ; aperture about equal in length tc 

 the spire; labium with an obvious plate of calcareous deposit; a 

 distinct and rather open umbilical aperture ; color pale reddish- 

 white or yellowish-white. 



Total length seven- twentieths. Inhabits South Carolina. 

 Of a dozen specimens sent me by 3Ir. Elliott, none exceeded 

 the limit here assigned to the species. It differs much from any 

 other species I have seen ; a variety of it, sometimes quite black, 

 •was found by Dr. M"Euen at Oswego, on the Susquehanna. 



It may be useful here to remark that, in consequence of a typo- 

 graphical error in the first part of the second volume of this work, 

 the species above described may be confounded with the de^iJiosu*. 

 The length of that shell is erroneously stated to be seven-twentieths 

 of an inch, instead of seven-tenths, its true length. 



Paludixa graxa. — Shell conic-ovate; whorls not perceptibly 

 wrinkled, convex ; suture deeply impressed ; aperture orbicalar, 

 hardly angulated above ; labium with the superior edge appressed 

 to the surface of the penultimate volution ; umbilicus rather small, 

 profound. 



Length less than one-tenth of an inch. Inhabits Pennsylvania. 



