KEY TO UROCOPTID^E. XXXV 



a 1 . Cusps with the cutting edges notched or serrate, all 

 the side teeth of about the same shape. 

 6. Mesocones merely notched or emarginate (xvi, pi. 

 14, fig. 8) . Shell tapering, with entire or slightly 

 truncate apex and usually discontinuous peri- 

 stome. Macroceramus, xvi, p. 113. 



& 1 . Mesocones with broadly expanded, serrate cut- 

 ting edges ; ectocones large. Teeth extremely 

 minute and numerous (xv, pi. 43, figs. 6-13). 

 c. Shell pillar-shaped, striate, reddish or brown, 

 Avith the axis coiled cork-screw-like in the 

 later or last whorls, and the peristome entire. 



Spirostemma, xv, p. 284. 



c 1 . Shell fusiform, very glossy and often varie- 

 gated, the axis straight, though often cal- 

 loused and truncate in the last whorl; peri- 

 stome widely interrupted above. 



Anoma, xvi, p. 1. 



Key to Genera, etc., by Shell-characters. 



* AXIS OF THE SHELL HOLLOW OB PERFORATE, though Usually 



closed at the base. 



I. Rather large forms, diam. 6 mm. or more, almost invari- 

 ably truncate. 



1. Axis rather slender, imperforate at the truncate sum- 

 mit, or showing only a small axial slit. 

 a. Axis slender, straight or slightly sinuous. 



Oligostylus, xv, p. 8. 



&. Axis slender, encircled throughout by a compressed 

 spiral lamella, median in each whorl ; upper part of 

 the truncate shell not abruptly tapering. 



Eucalodium, xv, p. 3. 



c. Axis rather strong, encircled in the last whorl or two 

 by a sub-basal cord or lamella ; upper part of the trun- 

 cate shell rapidly tapering. 



Anisospira, xv, pp. 24, 298. 



