+ A. E. Verrill on the Mollusca of Kurope and N. America, 
odon fluviatilis, and A. undulatus are put 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. 
cartosus, occur even in Maine. Some of them (as U. radiatus, 
M. undulata, and A. fluviatilis) 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, Hyalina, Macrocyclis, 
Limax, Pupa, Vertigo, Succinea, Arion, Zonites, Tebennophorus, 
Limnea, Physa, Bulinus, Planorbis, and Ancylus are set down 
as having the northern distribution, except Hyalina Binneyana, 
Pupa fallax, Limnea catascopium, 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 H. Binneyana and P. ancil- 
larva certainly 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. Hven Dr. 
Stimpson’s ‘‘Shells of New England” (1851), if consulted, 
might have saved most of the errors in regard to the distribution 
of the marine shells. 
The fact 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. Jeffreys 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 
errors of this kind, leaving the rest to be discussed more fully 
elsewhere. 
Kvery naturalist should be willing to allow his fellow natu- 
ralists full liberty of opinion with respect to the specific identity 
