762 



NORTH AMERICAN INDEX FOSSILS. 



CXLVIII. Buccinofusus Conrad. 

 Large and stout fusoid shells with round, rapidly increasing 

 whorls, short canal scarcely contracted at the anterior end which 

 is slightly reflected; ribs and spirals coarse, the former becoming 

 fainter in the adult shell. Differs from Siphonalia chiefly in its 

 straighter canal, and wider more patulous aperture. 



519. B. parilis Conrad. (Fig. 1109.) Miocenic. 

 Whorls round, contracted rather rapidly to long, slightly re- 

 flected canal; aperture wide; ribs strong on younger, weaker on 

 adult whorls ; round and broad spirals uniformly strong, with 

 numerous threadlike intercalated secondary spirals between each 

 pair of primary. 



Chesapeakean of Atlantic coast. 



CXLIX. Siphonalia Adams. 

 Short, thick-set fusoid shells with ribs and spirals, or with 

 spirals only and with short, strongly reflected anterior canal. 

 Eocenic-Recent. 



520. S. devexa (Conrad). (Fig. 11 10, a.) Miocenic. 



Fig. 1 1 10. a, Siphonalia devexa; b, S. migrans, both X %- (Md. Survey.) 



Shoulders concave; angle blunt; ribs concentrated on angle, 

 dying away in either direction ; spirals numerous ; frequent inter- 

 calations ; canal sinuous. 



Chesapeakean of Atlantic coast. 

 521. S. migrans (Conrad). (Fig. 11 10, b.) Miocenic. 



Last whorls non-angulate, without ribs, with numerous spirals; 

 angulation of early whorls less pronounced. 



