14 THE NAUTILUS. 



1865, none seemed to have found it. Dr. Lewis in his Freshwater 

 and Land shells of Alabama (Geol. Sur. Ala. Rep., p. 25, 1876) 

 gives no further information but states that in the absence of the 

 operculum it is uncertain whether it should be referred to Neritella 

 (= Neritina). Binney was uot able to add any further information 

 in his Land and Freshwater shells of North America. I find in one 

 of my books a manuscript note by a very competent conchologist 

 which declares under date of 1884 that this shell is the young of 

 Anculosa ampla Anth. "Under Neritidce in the Manual of Coucho- 

 logy (vol. x, 1888) Mr. Tryou observes that it has not the char- 

 acters of Anculosa, on the contrary it more nearly resembles Nerifniu 

 crepiduluria, though the coloring of the epidermis is more like that 

 of Anculota than in the other fluviatile species of Neritiim. 



For some years I have used every opportunity to seek further in- 

 formation about this species but without success, until lately Mr. 

 Bryant Walker of Detroit informed me that he bad found, among 

 shells collected on the Cahawba River in Alabama, by Prof. R. E. 

 Call, a single specimen which he had referred to Lea's species. 

 This he was kind enough to send me for examination and on com- 

 parison with the types it proved identical, thus establishing the 

 correctness of the American habitat of the shell which had been so 

 long in doubt. The specimen had also the operculum, which was 

 not that of a Neritina, but the soft parts had been removed. 



A comparison was then made with the young of all the species of 

 Anculosa in the National collection, which resulted in confirming Mr. 

 Tryon's opinion that it could not be referred to that genus. Dur- 

 ing this search, under the head of " Anculosa atnpla, very young'' 

 were found three additional specimens of the so-called Neritina, 

 received under that name from Dr. Lewis, who in turn had received 

 them from Mr. T. H. Aldrich who had collected them from the 

 Cahawba River, Alabama, thus fixing a second locality for the 

 species. The smallest of Dr. Lewis's specimens fortunately contained 

 the operculum and dried remains of the soft parts which were put in 

 soak and boiled in potash finally revealing an extremely minute 

 rhipidoglossate radula, in general uot unlike that of Neritina but 

 uot like that of any species of Neritina yet figured. The differences 

 are such as would ordinarily be regarded as generic and, taken into 

 consideration with the operculum, it becomes evident that, while the 

 species is related to Neritina (and not to Ancnlosa), a new genus 

 must be instituted to receive it. 



