﻿•i A. E. VernJl on the MoUusca of Europe and JV. Ameriea. 



odon jiuviatilis, aud A. undulatus are jnit down as southern. It 

 would certainly be difficult to show that these, as a group, are 

 more southern than the previous lot ; for most of them have 

 nearly the same wide distribution, and all of them, except U. 

 cariosiis, occur even in Maine. Some of them (as U. radiatus, 

 M. undidata, and A. ftnviatilis) are the most abundant species in 

 all the waters of northern New England and New Brunswick. 

 The distribution given for the species of Valvata^ Melantho, and 

 Amnicola is equally faulty. 



All of the eighty-one species of Helix, Hyah'na, Macrocyclis, 

 Lhnax, Pupa, Vertigo, Succinea, Avion, Zonites, Tehennophorus, 

 Limncea, Physa, Bidinus, Planorbis, and Ancylus are set down 

 as having the northern distribution, except Hyalina Binneyana, 

 Pupa tallax, Limneea catascopiian, and Physa ancillaria. But 

 every American conchologist knows that nearly all of those 

 species are very widely distributed over North America, east, 

 west, north, and south, many of them being limited only by the 

 Gulf of Mexico on the south and California or the Pacific on the 

 west Nor is there any reason for the distinction made in the 

 case of the four species named above ; for these, though differ- 

 ing among themselves, have the same distribution as many of 

 those put down as northern, while //. Binneyana and P. ancil- 

 laria certainl}" have a very northern range, for they are abun- 

 dant in Maine, New Brunswick, and Canada. 



It is evident that such numerous errors of this kind render 

 the paper, so far as geographical distribution is concerned, 

 quite worthless ; for it is sure to mislead. 



Most of these errors might have been easily avoided had the 

 author depended less on Gould's work and more on the recent 

 works of American conchologists ; for there is no lack of data 

 in regard to the distribution of most of our shells. Even Dr. 

 Stimpson's " Shells of New England" (1851), if consulted, 

 might have saved most of the erroi*s in regard to the distribution 

 of the marine shells. 



The tact that there is in the southern and shallower parts of 

 the Gulf of St. Lawrence an isolated colony of southern shells, 

 may have misled Mr. Jeftreys in many cases, especially as he 

 evidently consulted the Canadian collections much more than 

 those of the United States, many of the largest of which he did 

 not see at all. In respect of erroneous identifications and the 

 reduction of certain species to varieties, there is also much to be 

 said ; but this article is already so long that it will be neces- 

 sary to refer only to some of the more obvious and important 

 erroi*s of this kind, leaving the rest to be discussed more fully 

 elsewhere. 



Every naturalist should be willing to allow his fellow natu- 

 ralists full liberty of opinion with respect to the specific identity 



