106 



should be acquiesced in as regards the other species, there would 

 remain eleven certain species, viz : 



P.fallax, Say. Synon. P. marginata, Say ; P. albilabris, Adams. 



P. armifera, Say. 



P. contracta, Say. 



P. rupicola, Say. Synonym, P. procera, Gould. 



P. pentodon, Say. Synonyms, P. curvidens, Gould ; P. Tappan- 

 iana, Adams. 



P. exigua, Say. 



P. ovata, Say. Synonym, P. modesta, Say. 



P. badia, Adams. 



P. milium, Gould. 



P. Gouldii, Binney. 



Dr. Gould made some verbal remarks on Dr. Binney's 

 paper. 



He concurred in most of Dr. B.'s conclusions. He allowed that 

 no one would be justified in making a species of such imperfect 

 specimens as Dr. B. had seen of P. simplex. Very few had as yet 

 been found ; but the characters of the entire specimens were so 

 distinct, that he felt confident it would prove a good species. P. 

 carinata, to be sure, was founded upon a single specimen, now 

 lost. But he did not think that a shell so peculiar in so many 

 respects could belong to any known species ; nor was he satisfied 

 that P. rupicola and P. procera were synonymous. The name P. 

 pentodon might well give place to one of the other names, inas- 

 much as it is a misnomer, the name having been given to the im- 

 mature shell, before the aperture was complete, and when only 

 five teeth were to be found ; or, it might be applied to the new spe- 

 cies described by Dr. B. The characters of the aperture agree 

 generally with P. curvidens ; but, if they are the same, there is an 

 extraordinary difference on account of locality ; the western speci- 

 mens, (P. pentodon,) being of a translucent spermaceti color, while 

 the eastern variety, (P. curvidens,) is a third smaller, opaque, and 

 covered with a thick, green epidermis. 



Dr. Storer read a critical notice of De Kay's Report on 

 the Reptiles of New York, in which he made several cor- 

 rections of errors occurring in that report. 



