250 NEW FOSSIL SHELLS 



Sciences; but our shell is much larger, more ponderous, with the apex more twisted, and 

 without the spines of the C. costata. I have a number of specimens of each now before 

 me, and I find that these characters obtain at all ages. 



C. CORNUCOPIA, PL. 35. FIG. 41. 



C. testa valde devata et convexd, Icevi, politu, crassa; apice terminali, valde producto, voluto, superne sub-angulato, 

 sinistrorsum deflexo; aperturd parvd, ovatd; cyatho profundo, piano, acie curvo. 



Shell much elevated, very convex, smooth, polished, thick; apex terminal, very much produced, whorled, some- 

 what angular above, turned to the left; aperture small, ovate; cyathus deep, flat, with the margin curved. 



Height .16. Length .30. Breadth .18 of an inch. 



Remarks. The apex is very far removed from the margin of the mouth; it is slightly 

 turned to the left, and has about half a volution. The aperture is ovate, approaching to 

 elliptical. The cyathus is situated deep in the shell, so that there is a large cavity under 

 the apex. It is perfectly flat, and its outer margin has a gentle and regular incised curve. 



I at first considered this curious little shell as identical with the C. convexa, Say, but 

 the differences in the apex and cyathus render the separation necessary. 



C. LAMINA, PL. 35. FIG. 42, 



C. testa, discoidale, pianissimo, tenui, l&vi; apice elevato, polito, sinistrorsum deflexo, anfractibus sesqui; aperturd 

 magnd, subrolundd; cyatho parvo, tenui, convexo. 



Shell discoidal, very flat, thin, smooth; apex elevated, polished, deflected to the left, with a whorl and a half; 

 aperture large, subrotund; cyathus small, thin, convex. 



Height .03. Length .18. Breadth .15 of an inch. 



Remarks. The most peculiar character in the species now before us, is in the shape 

 of the apex. This is perfectly smooth and polished, rising suddenly from the flat back 

 of the shell, and twisted into about a whorl and a half. The margin of the mouth 

 projects anteriorly beyond it, so that it is invisible on a front view. There are small 

 concentric lines of growth over the surface of the shell. The cyathus is slightly and 

 regularly convex. 



When very young, this species, from the peculiar formation of the apex, has a striking 

 resemblance to a small Natica, and I have been for some time in doubt as to what genus 

 a specimen of that age belonged. 



This shell is closely allied to the C. plana, Say, but the peculiar apex and nearly flat 

 cyathus at once distinguish it. 



FAMILY BULL^IDJE. 



GENUS BULLA. 

 B. CYLINDRUS, PL. 35. FIG. 43. 



B. testa sub-ellipticd, superne et inferne acuminatd, crassa, politd, slriatd; spird umbilicatd; anfractu ultimo ad 

 basim et apicem slriato; aperturd falcatd, inferne latd; colUmelld rejlectd. 



Shell subelliptical. acuminate above and below, thick, polished, striate; spire mnbilicate; last whorl striate at the 

 base and apex: mouth falcate, wide below; columella reflected. 



