68 CONCHOLOGIA CESTRICA. 
RP. lata, Tryon, Contin, FE. W. Moll-U: S: 
P.lata. Shell, very fragile, light horn color, waxy, 
He Ee irregularly striate; spire moderately elevated; 
whorls convex; apex acute; suture well im- 
pressed; body inflated; aperture rather large; 
columellar lip turned to the right, very narrow, 
distinctly folded. H. 10.5, W. 7, mill. 
Station, Juniata River, Hollidaysburg, Penn- 

sylvania. 
Oss.— This species not having fallen under our ob- 
servation, the figure and description have been taken 
from the recent admirable continuation of Haldeman’s 
Monograph of the Fresh Water Univalve Mollusca, by 
G. W. Tryon, Jr., who observes that “this species has 
very much the form of P. heterostropha, Say, but is 
rather more ventricose, much thinner, and the surface 
exhibits a peculiar, glimmering lustre.” 
Genus BULINUS, Apanson, 1757. 
AnimalopRulinius Shell, sinistral, elongated, polished, 
Fig, Be thin, acuminate ; aperture narrow, pro- 
oy 
duced anteriorly. 
Animal, tentacles filiform, seta- 
ceous; mantle simple, not fringed, and 
not reflected over the shell, as in Physa. 
B. hypnorum, LINN. 
Physa hypnorum, Linn., Syst. Nat., 1758. 
B: ee Shell, oblong, fragile, diaphanous; whorls 
Fig, 135, 6; spire acute; aperture not dilated, atten- 
uated above, half the length of the shell; 
A columella narrowed at the base. H. 17, 
K W. 7, mill. 
Ly Station, in flowing streams, and stagnant 
pools. New Garden, Chester County; rare. 
