134 



NORTH AMERICAN INDEX FOSSILS. 



the only other known American Clymenia, Acanthoclymenia nea- 

 politana (Clarke), in its more simple suture and the presence 

 of ribs. 



Common in the upper part of the Three Forks shale at the top 

 of the Upper Devonic, at Three Forks, Montana. 



Fig. 1385. Platy clymenia americana ; b, y^ ^•, a and c, opposite sides of fragment, 

 X 2. (After Raymond.) 



Bactritida (Bactritidce). 

 LXXIV. Bactrites Sandberger. 

 Straight shelled like Orthoceras, with simple sutures except for 

 sutural (ventral) lobe. Devonic. 



195. B. clavus Hall. (Fig. 1386.) Devonic. 



Fig. 1386. Bactrites clavus^ 

 X%- (After Hall.) 



Fig. 1387. a^ Bactrites gracilior^ a frag- 

 ment ; b, B. aciculum. (After Clarke and 

 after Hall. ) 



