ICHTH'YOCRINIDAE 303 



the great disparity in size of the large one I am unable to see any specific difference between 

 them. The sharply angular distal end of the posterior basal, constant in all the specimens, 

 precludes any suggestion of anal structures. Since the foregoing description was prepared 

 I have obtained from the type locality in Erie County another still larger specimen, measuring 

 45 mm. high by 35 mm. wide. It is so encrusted with pyrites that the detailed structures are 

 obliterated, but the nodose axillaries are almost spiniferous. 



Hall in describing the species noted its remarkable resemblance to " Forbesiocrinus " 

 thiemeij now the type of Wachsmuthicrinus, as well as its difference from that species in arm 

 structure. This resemblance is heightened by the nodose and spiniferous character of the 

 axillaries so conspicuous in the specimens found since his time. 



Types. Hall's original is in the American Museum of Natural History, New York. 

 That of figure 5 is in Columbia University. The others are in the author's collection. 



Horizon and locality. Middle Devonian, Hamilton Group ; Eighteen Mile Creek, Erie 

 County, and Bellona, Yates County, New York. 



