14 THE NAUTILUS. 
uable addition to the food supply of the West Coast. It seems 
strange that some of the conchologists or collectors should not have 
detected the Urosalpinx before; for while, no doubt it multiplies 
rapidly under favorable conditions, still the abundance of this form 
as shown by Mr. Townsend’s investigation, indicates that it must 
have been on the Belmont beds for several years. The common 
Purpura of the coast, P. erispata has heretofore been found in con- 
siderable numbers on some of the oyster beds in San Francisco Bay. 
How it compares with the dri//, as an oyster borer and pest to the 
oyster men, I have not learned. 
We may reasonably look forward to the finding of a third eastern 
species, as an accidental or incidental transplantation ; it may be 
already established there, in some of the beds of eastern oysters. 
I refer to the ribbed Mytilus, M. hamatus Say, which is so frequently 
met with here, attached to Ostrea virginica. Mr. Townsend or 
some of the local naturalists, should look after it—if not there now, 
it will be sooner or later. 
Washington, D. C., March, 1894. 
A FEW NOTES ON HELIX APPRESSA. 
BY A. G WETHERLY. 
In the April Naurinus, Mr. Pilsbry has given us his description 
of Triodopsis appressa, and named a variety thereof, perigrapta. As I 
am at war in a good humored way, with the modern habit of desig- 
nating the hundreds of varieties of our land shells by latin names, 
I hope to make my reasons plain in the following brief note. Re- 
ferring to, but not copying Pilsbry’s description of perigrapta, I will 
say that I have shellsin my collection exhibiting every gradation of 
the sculpture in question, from a few “spiral incised lines ” in speci- 
mens from Cherokee Co., N. C., to those in which these lines are not 
only crowded, but much more pronounced individually ; and as 
these specimens are heavily ribbed, they aid in giving some parts of 
the surface of the shell a beaded appearance. 
Every gradation may be traced in the specimens which I have, 
from the smooth albino form found at Cincinnati, Ohio, to those 
rough mountaineers from Morrowville, Tenn. Where then, does 
