CONTRIBUTIONS TO PALAEONTOLOGY. 93 



I am unable to find any characters in the Moravia specimens, to separate 

 them from the others. I cannot therefore recognize the CryphcBus greeni as 

 a distinct species. The Cryphjeus is common at York ; and I am induced 

 to believe that the specimens referred to Asaphus halli are this fossil with 

 the fimbria removed, or the border separated. Extensive collections from 

 York have not served to produce any other Trilobites than the Dalmania 

 (Cryph^us) and Phacops. 



Geological formation and locality. In the Hamilton group : at Hamil- 

 ton ; shores of Cayuga, Seneca and Canandaigua lakes ; Geneseo, Moscow, 

 York, Pavilion ; and at Eighteen-mile creek on Lake Erie. 



GENUS PHACOPS (Emmrich). 



/ 



PHACOPS BUFO ( Green, sp.) /O h'j > 'I 



Calymene hufo : Green, Monograph, p. 41. 

 The geological position of this species is not stated by Dr. Green, but 

 it is said to have been found in New- Jersey in a dark greyish limestone. 



PHACOPS RANA ( Green, sp.). 



Calymene bufo, var. rana : Green, Monograph, p. 42. 



Prof. Green has described ( Monograpii, p. 41) the Calymene bufo, the 

 original of which is a specimen having " a length of four inches and a half," 

 and "the breadth of the buckler nearly two inches." 



I have never seen, in the rocks of New-York, an entire specimen of this 

 genus having a length of more than two and a half inches. Some separated 

 heads are an inch and an eighth long, and the length of the head in the 

 common species is about one-third the entire length of the animal, which 

 would give a length of less than three and a half inches for the largest 

 specimen. The proportions of C. bi/fo do not agree with any specimens in 

 the Upper Helderberg rocks or in the Hamillon group. 



In an individual from the Hamilton group, of two and a quarter inches 

 long, the width of buckler at base is one inch and a quarter ; and in 

 another of one inch and a half long, the width is about seven-eighths of an 

 inch. The proportions given by Green would clearly indicate his C. bif'o 

 as a distinct species. 



The Calymene bufo^ var. rana, is cited by the same author as occurring 

 at Seneca, Ontario county, N.Y.; which locality is in the shales of the Ha- 

 milton group. Specimens are common, and sometimes abundant in the shales 

 of the Hamilton group ; and a species, which I regard as identical with 

 this, occurs in the upper limestone of the Upper Helderberg group. 

 186L3 



