62 AMERICAN JOURNAL 



seem certain that they can be identified with shells from Cayuga 

 Lake, N. Y., — Say's original locality. 



" Amnicola orbiculata, Lea," may be, and very probably is, as 

 Mr. Lea himself suspected, identical with porata. The locality 

 (the same as Say's) suggests in a very positive manner that this 

 is so. 



Pomatiopsis lustrica, page 94. Can it be possible that Mr. B. 

 has a true Pomatiopsis under this name ? If so, is it not the 

 same shell which a few pages earlier he calls Amnicola Sayana, 

 and confounds with a species of aquatic habits, that Say called 

 Paludina lustrica ? This really seems to be the case. But, 

 whatever may be the state of the case in Mr. Binney's hands, 

 the matter must be examined methodically. The type of the 

 genus Pomatiopsis is the species lapidaria. We have as yet only 

 one other species well determined by its lingual dentition and its 

 habits as a Pomatiopsis, and that is the shell Mr. Binney called, 

 a few pages further back, " Amnicola Sayana," and which is 

 now brought into its proper place as Pomatiopsis cincinnatiensis, 

 Lea. We find a similar and smaller shell of aquatic habits, which 

 is presumptively the shell Mr. Say called Pal. lustrica. We do 

 not know yet from its anatomy that it is an Amnicola, but so 

 much of its habits and external characters as have been observed 

 go to suggest that if it be not an Amnicola it is nearer, generi- 

 cally, to Amnicola than to any other genus the characters of 

 which have been determined. It is very nearly allied in some of 

 its characters to that species known as Amnicola cincinnatiensis, 

 Anthony, page 85. 



Among the shells erroneously referred to " Pomatiopsis lus- 

 trica" are certain specimens from the "Mohawk River," N. Y., 

 No. 8975. The shells sent to the Smithsonian Institution were 

 labelled Amnicola lustrica. They were subsequently regarded 

 as Amnicola grana, Say, and the soft parts described under that 

 name, as stated further back. Later they were recognized as 

 being identical with shells described by Mr. Lea, under the name 

 Paludina obtusa. They are now known to be the same as those 

 Mr. Binney calls Bythinella obtusa, and should have been so re- 

 ported by him. The generic place of this species has not (as is 

 stated further back) been as yet satisfactorily determined. 



A careful examination of Mr. Binney's references of specimens 

 to species by their Catalogue numbers, shows very conclusively 

 that he accepted a great many specimens on trust, without giving 

 them that careful consideration which alone should determine 

 their generic and specific places. This state of things being 

 conspicuously apparent in several notable instances, the query 



