134 THE NAUTILUS. 



Gould and others, to be a distinct species. It is evident from the 

 museum register given by Binney, that he had no Canadian exam- 

 ples of the species before him, although he remarks that he " had 

 seen no specimens from the localities visited by Mr. Say while on 

 Long's expedition that were not forms of P. trivolvis." 



Tryon, in his supplement to Haldeman, affirmed Binney's opinion, 

 referred corpulentus to trivolvis, and described the western form as 

 P. binneyi. 



This decision, so far as it differentiates the west coast form from 

 Say's corpulentus, is undoubtedly correct, and all the west coast cita- 

 tions of that species must be eliminated. 



Following the lead of eastern naturalists, the species has been 

 cited either specifically, or as a variety of trirolvis in many of the 

 eastern local lists, but without description or remarks. Such are 

 Anthony, " Cincinnati ; " Wheatley, " New York to Ohio ; " Hub- 

 bard, "Ohio," and Lewis, " Little Lakes, N. Y." 



Jay is the only one of the eastern cataloguers who appears to have 

 had a specimen from near the original locality, and which possibly 

 may have been true. He gives the locality of his example as " Win- 

 nepeck river." 1 



It follows therefore that all the citations of this species from the 

 eastern and central states must also be rejected. 



There thus remain for consideration only the few citations from 

 the Manitoba region of Canada and the northern central part of the 

 United States. Say's original description cites the Winnepeck river, 

 Winnepeck Lake, Lake of the Woods aud Rainy Lake. Dawson in 

 the " Report of the British North American Boundary Commission," 

 quotes it from Flag Island, Lake of the Woods, and remarks that 

 " the specimens are from Say's typical locality and agree perfectly 

 with his description. If P. corpulentus is a variety of trivolvis, as 

 has been suggested, it is a very well marked one, and is character- 

 istic of the open reaches of the lake." 



1 Part of Say's collection is now in the American Museum of Natural History 

 of New York. Mr. R. P. Whif.field, the Curator, writes: " We have in the Say 

 collection one shell from the Winnepeck river, but it is not the one figured by 

 Say in Long's Expedition, but is smaller, lacking the outer volution as com- 

 pared with that figure. We have one quite large specimen from the J. J. Cooke 

 collection from Lake Superior, and four specimens from the W. A. Haines' col- 

 lection, which are labelled Winnepeck river. But I can find no evidence as to 

 who collected them or where." 





