CONTRIBUTIONS TO PALAEONTOLOGY. 193 



" In 1847, Professor Hall suppressed the genus Cypricardites, and sub- 

 stituted his own genus Modiolopsis, in which he placed all Conrad's Lower 

 Silurian species." 



Had these remarks of Mr. Billings concerned myself alone, I 

 would not have noticed them; but as I am charged, in a respectable 

 journal, with suppressing a genus proposed by Mr. Conrad, and 

 with holding in my hands " for eighteen years without publication" 

 a figure showing the characters of the hinge, I cannot, in justice to 

 Mr. Conrad and myself, do otherwise than communicate a copy of 

 the lithographic plate to which I originally referred, and which was 

 published with his Report in 1841, and circulated with some but 

 not with all the copies. 



I proposed the Genus Modiolopsis, not as a substitute for Cypri- 

 cardites, but because the species included under that name did not 

 appear to be congeneric; and I separated some of those which did 

 not possess the typical marks of Cypricardites. 



With regard to the propriety of adopting the name Cypricardi- 

 tes, on account of a zoological error involved, it is scarcely worth 

 while to offer argument. We have too many analogous cases, and 

 that of the Genus Athyris may serve as an illustration. Mr. Conrad 

 is doubtless entitled to the priority of discovery, description and 

 illustration of the characters of the Genus Cypricardites; and I 

 cannot suppose that another generic term, applied to shells of pre- 

 cisely the same character, will supersede the original name. 



In reference to the Genera Megalomus and Megambonia*, I can 

 have no controversy with Mr. Billings. If naturalists are content 

 to accept his assertions without other evidence, I shall not complain : 

 the typical species will remain, and may, at some future time, be 

 studied without passion or prejudice. 



* A small amount of conchological knowledge is sufficient to show that these forms 

 are not only generically distinct, but that they belong to a different family of shells 

 from those described as PALiEARCA or Cyetodonta. 



[Senate, No. 1]6.] 25 



