86 THE NAUTILUS. 
them teeth, the thinner shells being as clear of teeth as a typical 
Mesodon, and only the old thickened shells have the obsolete teeth, 
They attain a size somewhat larger than the largest specimens of 
inflecta in the Binney collection. 
Prof. Call believes them to be Triodopsis appressa minor, but they 
seem to me to be nearer inflecta than appressa, and if not a distinct 
species, they certainly are a well-marked variety. 
NOTES ON THE VARIATION OF CERTAIN MOLLUSCA 
INTRODUCED FROM EUROPE. 
BY T. D. A. COCKERELL. 
As IT have urged when writing of Helix nemoralis, few subjects can 
be more interesting to the conchologist than the effect of environment 
on species, which is seen so frequently in the case of variable species 
introduced into new countries. 
Through the kindness of Mr. W. G. Binney and Prof. J. H. 
Morrison, I have been enabled to examine specimens of several 
species of European Mollusca introduced into this country, and to 
refer them to various varieties already known in Europe, but mostly 
so far not recognized in the American fauna. 
(1.) Agriolimax agrestis (L.) var. Sylvaticus. (Moq., non Drap.) 
This is the mottled form of the species, and appears to be the 
prevalent form at Burlington, New Jersey, whence Mr. Binney has 
sent me several living examples. One of these is unusually large, 
being 53 mill. long. 
(2.) A. agrestis var. typica. (Less. & Poll.) 
This is the spotless type, of which I found a single example at 
St. Thomas, Ontario, Canada, in 1887. 
(3.) A. agrestis var. reticulatus (Moq.) 
Resembles var. sylvaticus, but is reddish-ochre with black irregular 
spots, often tending to reticulation on the body. Sent from Burling- 
ton, N. J. (Mr. Binney). 
(4.) Limax (Lehmannia) variegatus Drp. var. flavas Moq. (—L. flavus ‘ L.,”’ 
Auctt.) 
Lexington, Va., one example from Prof. Morrison. 
