528 



NEW YORK STATE MUSEUM 



Above base of Wolf creek conglomerate 



Leptodesma orodes 



curvatum 



maclurii 



mytiliforme 



« 



ii 



a 



Below base of Wolf creek conglomerate 



Mytilarca chemungensis 

 Nucula bellistriata 



Pterinopecten 2 sp. 

 Dictyospongia 

 Prismodictya 2 sp. 

 Thysanodictya 2 sp. 



Pararca 3 sp. 

 Ptychopteria 8 sp. 

 Palaeanatina 2 sp. 

 Bothriolepis 

 Ctenodus 

 Holoptychius 

 Gyracanthus 

 Fishes 



It becomes quite clear that a fundamental change has 

 entered on the nature of the fauna with the deposition of the 

 Wolf creek conglomerate and in the species herewith commenc- 

 ing their existence we find a certain well defined aspect of Car- 

 bonic life, the presence of which is supplemented by the abrupt 

 disappearance of the leading features of the Chemung fauna. 

 We have made special reference toOehlertella pleu- 

 rites and have already in another place discussed the char- 

 acters of the Agelacrinites buttsi from the stratum 5 

 which shows a close affinity to cystids of the early Carbonic. 

 It is to be further noted that the post or supra-Carbonic aspect 

 is indicated by the Ptychopterias and Pararcas rather than a 

 true Devonic though the presence of heraldic forms of these 

 genera in Devonic strata is not to be questioned. Yet here by 

 their profusion they indicate a faunal aspect which is peculiar 

 to this horizon. Attention may be directed to the presence of 

 fish remains which have been found in the red beds of stratum 

 no. 7, and of them some, like Holoptychius ameri- 

 canus, may be regarded as suggesting the horizon of the Cats- 

 kill of eastern New York, while others, Gyracanthus, Cteno- 

 dotus and Bothriolepis point with more definiteness to a higher 

 horizon. 



