THE NAUTILUS. 31 



the " elevated and rather obtuse " spire would apply better to 

 "obtusa." In view of this uncertainty, it would seem better to 

 accept a later description, in regard to which there can be no ques- 

 tion, rather than to attempt to rehabilitate a name which must 

 always be the object of suspicion. There should be a statute 

 of limitations in science as there is in law; and the use of a name? 

 which has become established by tradition and long usage, should 

 not be overturned, in the absence of the type specimens, excepting 

 upon the most convincing proof. 



In 1852 Ku'ster, in his " Monograph of Paludina," in the Con- 

 cliylien Cabinet, describes a small species from North America as 

 Paludina emarginata, which he attributed to Say, on the authority 

 of Brown. As Say never used the name " emarginata " in connec- 

 tion with any fresh-water operculate form, this species will have to 

 stand as Paludina emarginata Kiister. 



Binney, in his "Land and Fresh-water Shells of North America" 

 (1865), refers Kiister's species to Amnicola cincinnatiensis Anth. as 

 a synonym. This was clearly erroneous, as a most casual inspection 

 of Kiister's description and figure quoted by Binney will show. 



Tryon makes no mention whatever of Kiister's " emarginata'' 

 in his continuation of Haldeman. 



What Kiister's species really was has been a matter of speculation 

 with me for many years. Recently, however, in reading Frauen- 

 feld's paper (1863) on the Amnicolce, in the Imperial [Vienna] and 

 Cuming Collections, I found a statement that specimens clearly 

 agreeing with Kiister's figure were in the Cuming collection labeled 

 " obtusa Whit." Now there was a well-known collector named 

 Whittemore, who lived in Massachusetts in 1840-1860, and it 

 seemed quite probable that he had supplied the Cumingian specimens 

 under Lea's name, but without quoting his authority. Then, too, 

 there was a very evident accord between Kiister's figure and his de- 

 scription and those of Lea's species. 



On applying to Mr. E. A. Smith, of the British Museum, for in- 

 formation in regard to the Cumingian specimens, I was favored with 

 the following statement : 



" The shells marked Amnicola ' obtusa Whit' in the Cuming col- 

 lection certainly are not cincinnatiensis Anth., and I believe that 

 you are right in considering them the same as obtusa Lea. They 

 agree exactly with Binney 's figure, Part III., p. 70, but are corneous 



