212 BULLETIN OF THE 



Ariolimax Anderson!. 

 See Plate V. Fig. F, showing the typical specimen in spirits restored. 



Ariolimax Hemphilli. 



Plate V. Fig. B, G. 



A variety maculatus, Cockerell, is figured in B. The Figure G is drawn 

 from a typical specimen, with the tail, the pore, and the locomotive disk. 



Ariolimax niger, J. G. COOPER. 



Plate V. Fig. A, gives a lighter-colored form ; Fig. I, the typical form; Fig3. 

 C and D, the caudal pore. 



Triodopsis inflecta, SAT. 



This has erroneously been quoted from the -Pacific Province, at the mouth 

 of Columbia Eiver. It is difficult to decide what species Middendorff had in 

 view. His words are thus translated : 



Let it not be objected that Helix ctausa up to this time has not been discovered 

 west of the Rocky Mountains. The Northwest Coast of America is almost wholly 

 unexplored conchologically, and I do not doubt that H. clausa will be there 

 found, just as I can now assert with reference to //. planorboides. Even the 

 American authors know this hitherto only from the Ohio and Missouri. Its dis- 

 tribution nevertheless appears to extend over the whole of North America, since I 



have received a great number of specimens of the same through Mr. , from 



Sitka, whereby it becomes incorporated with our Russian Fauna. Southwards it 

 extends to the west coast of America, at least to Upper California, where they 

 were likewise collected by Mr. . It appears to have undergone no altera- 

 tion whatsoever, and presents in Sitka a considerable size, as the ordinary repre- 

 sentations show (up to 22, etc.). Moreover, Binney in the Boston Journal, III., 

 Plate XIV., has them copied equally large. 



Polygyra Roperi, PILSBRT. 



Shell umbilicated, plane above, slightly inflated below, shining, pellucid, 

 light horn-color, with delicate wrinkles of growth ; spire flattened ; whorls 5^, 

 scarcely rounded, very regularly increasing, the last flattened 

 above, abruptly deflected at the aperture, deeply constricted 

 behind the peristome ; aperture transversely lunar, gaping, 

 much contracted, tridentate ; peristome thickened, broad, 

 white, gradually thinning and scarcely reflected at its edge, 

 and not extending beyond the surface of the whorl, its ends 

 . approached, joined by a light callus, on which is a heavy 

 enlarged. white callus bearing a stout, white, broad, blunt, transverse 

 tooth, slightly curving inward, its basal margin with an erect 

 conical, short tooth, separated by a small circular sinus from another rather 

 more deeply seated similar tooth on its upper margin. Umbilicus broad, 



