160 Trans. Acad. Sci. of St. Louis. 



concave fasciolar surface below the usually well-developed 

 subsutural collar and frequently tending to disappear on the 

 larger whorls, a very short aperture, short, angulate base 

 with nearly obsolete canal, open anal sinus of the usual form 

 in Clavus and a conical pointed smooth multispiral and closely 

 coiled embryo. Among the typical species maybe mentioned 

 depygis Con. (= laevis Con. and pinaculina and solitariuscula 

 DeGreg.), with its varieties lonsdali Lea and surculopsis and 

 Jita De Greg., of the Upper Claiborne ferruginous sand and 

 texana Con. { = texacona Harr.), of the Lower Claiborne of 

 Texas. It is possible that such forms as tantula Con., of the 

 Vicksburg Oligocene, may also be included, although in that 

 species there is no well-defined subsutural collar and the ribs 

 attain the suture above. Ehoroides^ of Conrad, is more 

 nearly a Olavus and cannot be included. 



Belini. 



The species of this small tribe are exclusively inhabitants of 

 European arctic and subarctic waters, as far as definitely 

 known to me at present. They are moderate or email in 

 size and of thin fragile substance, frequently having a whitish 

 coating which is difficult to remove in many cases, and, in 

 others, such as Typhlomangilia and Bela pyramidalis Strom., 

 bears the characteristic sculpture of the shell. The embryo 

 varies in a most remarkable manner and serves to indicate, 

 with other accompanying characters, some six or seven 

 genera among the present representatives of Bela. Coss- 

 mann has referred several fossil forms to the genus Bela 

 in its broad sense, but there is some doubt if any of them 

 belong to the present tribe. The Australian Eocene ** plesio- 

 type " Bela pulchra Tate, certainly resembles some forms 

 allied to Clathurella more than it does the Belini, especially 

 in the conformation of the posterior parts of the aperture, but 

 the large obtuse embryo would isolate it there, though scarcely 

 more so than the American Eocene Eoclathurella to be de- 

 scribed below. In any event ^eZa pulchra will form the type 

 of a very distinct genus, probably assignable to the non- 

 operculate series. 



