1887.] NEW YORK ACADEMY OF SCIENCES. 137 



The fishes of our Triassic rocks are all ganoids and belong to 

 six genera, viz., Dij)lur2is,'Newh., Ischypterus,Egt., Catopterus, 

 Redf., Ptycholepis, Kg., Didyopyge, Egt., and Acentrojjhorus, 

 Traq. Of these Diptenis was a large Coelacanth attaining a 

 length of three feet and closely allied to Holophagus, Egt., of the 

 English Lias. Ptyclioleiyis, Acentropliorus and Didyopyge are 

 each represented but by a single species; while of Catopterus 

 there are five and of Ischypfe7'us e\ghteeu. All the species are 

 distinct from any known in the Old World, but a species of 

 Ptycholepis allied to ours, though distinct, is found in the Lias 

 of Boll, Wurtemburg, and a species of Dicfyopyge has been de- 

 scribed from the Keuper of Germany. Catojjterus seems to be 

 distinct from any genus of fossil fishes found in the Old World, 

 but Iscliypiterus is very near to Semionotus, kg., Avhich is repre- 

 sented by species in both the Lias and Trias of Europe. These 

 genera are indeed so nearly allied that it is somewhat doubtful, 

 whether they should be separated. Acentropliorus, Traq., is 

 very near to Ischypteriis; apparently differing from it only by 

 the absence of the spiny scales on the dorsal line. Of this we 

 have only one species, found at Chicopee Falls, Massachusetts. 

 The following is a list of the fishes found in our Triassic rocks. 

 Fragments obtained in the Richmond Coal Basin indicate the 

 presence there of another and as yet undescribed genus and a 

 large species of Dictyopyge different from />. macriira, Egt. 

 Diphirus lojigicaudatus, Newb. 

 Ptycliolepis Marshii, '' 



Acetitrojjhorus Chicopensis, " 

 Dictyopyge macrura, Redf., sp. 

 Catopterus Recliieldii, Egt. 



'' gracilis, J. H. R. 



'' anguiliformis, W. C. *R. 

 " parvulus, " 



" ornatiis, Newb. 



Iscliypterus Agassizii, W. C. R. 

 " ovatus, '* 



*' parvus, " 



" macropterus, " 



" Marshii, " 



