AFFINITIES OF THE FAUNA 235 



States Geological Survey, number 391). Two forms first described by 

 Kindle from Colorado, Spirifer notabilis and 8. whitneyi animasensis, 

 are among the common spirifers of the Canadian section. 



The Hamilton and Chemung species are the more cosmopolitan species 

 of the Devonian of New York and the Mississippi Valley. 



Since Spirifer roclcymontanus and 8. cameratus are widely distributed 

 species, their presence in the Lake Minnewanka region indicates merely 

 a broad general relationship with the Pennsylvania!! of the Mississippi 

 Valley and the Rocky Mountains. 



Description of Species 



devonian 



Spirifer notabilis Kindle 



The Canadian specimens show distinctly the characteristic slender 

 mucronate extensions, and especially the most striking peculiarity of 

 this species as described by Kindle, 2 namely, the nature and direction of 

 the plications on the wings. The first six plications on each side of the 

 sinus originate at the beak and diverge anteriorly, as usual in Spirifer. 

 The remainder of the plications, however, lying between these and the 

 extremities of the hinge originate at the hinge line instead of at the beak, 

 thus constituting a second series of plications with a different direction 

 from the former. Where the two series meet there is a marked diver- 

 gence, the outer series bending abruptly away from the inner. Lamellose 

 concentric growth lines cross the radiating plications. 



Range. — Spirifer notabilis has been found in Colorado and New Mex- 

 ico. In the Lake Minnewanka section it characterizes the transition beds 

 between the Lower Banff shale and Lower Banff limestone. 



Spirifer whitneyi animasensis (Girty) 



This variety is distinguished from the species by the highly elevated 

 area of the pedicle valve and its slightly twisted and but slightly incurved 

 beak. The plications are very fine and of about equal size over the whole 

 shell. 



Range. — Described by Girty from Colorado and by Kindle 3 from New 



2 E. M. Kindle: The Devonian fauna of the Ouray limestone. U. S. Geological Survey 

 Bull. 391, p. 26, pi. 7, fig. 3-Gc. 



■ B. M. Kindle: The Devonian fauna of the Ouray limestone. U. S. Geological Survey 

 Bull. 391, p. 25, pi. 9, figs. l-3o. 



XVII — Bull. Gbol. Soc. Am., Vol. 24, 1912 



