Weller — Kinderhook Faunal Studies. 



125 



The composition of the Chonopectus sandstone fauna is 

 as follows : — 



Of these genera and species, the brachiopods are for the 

 most part strongly Carboniferous in aspect. The abundance 

 of Productus is particularly a Carboniferous characteristic of 

 the fauna, as is also the presence of 8yringothyris. Of the 

 two species of Spirifer, one, S. subrotundatus, with its com- 

 pletely plicated shell and with the plications on the lateral 

 slopes bifurcating, is strongly carboniferous in aspect, while 

 S, bipUcatus, on the other hand, with its excessively elongate 

 hinge-line, has just as strong a Devonian aspect. The shell 

 identified as JSchizophoria swallovi is far more like the Car- 

 boniferous than the Devonian representatives of the genus. 

 The presence of Productella may be considered as a Devonian 

 element, and also Orthothetes inaequaUs, which is so nearly 

 like O. chemungensis. 



The pelecypods have quite a different story to tell, and 

 from a study of this portion of the fauna alone, one would 

 perhaps be justified in identifying it as of Devonian age. 

 All of the nineteen genera, with the exception of two. Pro- 

 macrus and Avicida, have numerous representatives in the 

 Devonian faunas of Eastern North America, particularly in the 

 Chemung faunas of New York and Pennsylvania, and several 

 of the genera have no representation later than Kinderhook. 

 Promacrus is a genus which is represented in America only 

 in faunas of Kinderhook age, and in Europe it has been noted 



