—_” 
THE NAUTILUS. dl7/ 
be mistaken. Generally smaller; somewhat elongate in outline, 
and so is the umbilicus; the spire is smaller, lower, and the suture 
less deep; the peristome is not everted, as in pulchella, but only 
slightly expanded. 
Group of V. costata. Ribbed; peristome with strong lip. 
3. V.costata Mull. Eastern North America to the Mississippi 
Valley, but less common than pulehella, though numerous in some 
localities. 
4. V.albula Sterki. Quebec, Manitoba to British Columbia. 
Larger than costata (2°7-2'8 mill.), whitish, with fine, crowded, 
membranous ribs; quite unlike any costata from Europe or North 
America. Also jaw and radula show differences, and so it was to be 
regarded as distinct, the more so as it has been found in company 
with costata at Quebec. 
5. V. gracilicosta Reinh. Utah to Dakota. Differs from costata 
by the stronger and more oblique ribs on the shell, and small or no 
membranous appendages on them; the Jast whorl and the aperture 
are more angular at the periphery, and more flattened above; the 
color is grayish, and the lip porcelain white, while in costata it is 
somewhat glassy transparent. 
6. V. parvula Sterki. Illinois to Nebraska and Indian Territory. 
Smaller than costata (diam. 2 mill.), the spire flat, the last whorl not 
descending. 
Group of V. cyclophorella. Peristome without a lip. 
7. V. eyclophorella Ancey. Rocky Mountains. Ribs very fine 
and crowded ; shell thin, grayish or whitish ; last whorl ascending 
and descending ; aperture transversely elongate; peristome thin, 
without a lip; diam. 2:7 mill. 
8. V. perspectiva Sterki. Appalachian Mountains, in Tennessee 
and Alabama; also in Iowa. Membranous ribs rather fine and 
crowded ; spire low; last whorl descending; peristome continuous 
without a lip; shell thin, pale horn to colorless; diam. 2°0 mill. 
ON THE GENERIC POSITION OF PATULASTRA? [PUNCTUM ?] PUGETEN- 
SIS AND PYRAMIDULA? RANDOLPHII, WITH SUGGESTIONS 
FOR A CLASSIFICATION OF AMERICAN ZONITIDZ. 
BY HENRY A. PILSBRY.! 
Specimens of the two species named above preserved in alcohol 
by Mr. Randolph, of Seattle, Washington, and kindly forwarded 
‘These species were described in NAUTILUS for March, 1895, p. 130. 
