I 



30 



Cincinnati Society of Natural History. 



specimens of his Ischyrodonta truncata labeled " Cypricardites 

 hainesi, S. A. Miller, a shell oecuping the same horizon." He 

 was, therefore, aware that his genus and species is from the 

 same horizon, and others had labeled it Cypricardites hainesi, 

 before he described it; but, he says " there is little reason for 

 confusing the two, since Miller's species has posterior cardinal 

 teeth, is less convex, and not so high posteriorly." These 

 are all the distinguishing differences he refers to, and as we 

 know of none other, we will proceed to examine the value of 

 these with the light we have before us. 



First. — We have been unable, from Mr. Ulrich's figures or 

 description, to discover that his species is any more convex 

 than Cypricardites Aainesi, and we have examined a great 

 many shells and casts with this point specially before us. 



Second. — We have been unable to discover that Mr. Ulrich's 

 figures or description show his species is any higher posteri- 

 orly than Cypricardites hainesi) and, on these two points we 

 are willing to submit the question to the judgment of compe- 

 tent paleontologists, upon offering, in evidence, the original 

 figures of the two specimens of Cypricardites hainesi, repro- 

 duced in North American Geology and Paleontology, on page 

 476, and the illustrations of Mr. Ulrich, on page 174, of Vol. 

 VI, of the American Geologist, with or without the types or 

 other specimens. We are perfectly satisfied there is nothing 

 in either of these two characters to distinguish the two 

 species. 



Third. — We now come to the question of the posterior car- 

 dinal teeth — a character of importance, if the differences 

 claimed by Mr. Ulrich have any existence, as a matter of fact. 

 We have not seen Mr. Ulrich's types, but as he drew his own 

 illustrations, and we think they are correct, it ought not to be 

 necessary to see the types in order to judge of the value of 

 the generic or specific characters. Here we may remark that 

 the casts of undoubted Cypricardites hainesi are just exactly 

 like the casts of Ischyrodonta truncata, and this is what we 

 would expect, if the two species were distinguished only by 

 the presence or absence of posterior cardinal teeth. The 

 casts of Cypricardites hainesi were found in the same cart- 

 load of earth with the types that were figured twenty years 

 ago, and the authors of this paper have collected them at 



