PHYSA. 



87 



Fhysa plicatn. 



lines ; suture distinct. Pillar-lip with a broad nacreous deposit. Aper- 

 ture more than two-thirds of the total length, acutely oval. 

 Amber, but coated with a black pigment ; before this is re- 

 moved, the aperture is bluish iridescent. Length 0.6-0.8, 

 of aperture 0.2-0.3 inch. 



Tliis description is from specimens of the largest size, 

 obtained from a pond on New York Island. It moves like 

 P. heterostropha, with great celerity on tlie surface of the 

 water, with its mouth downward. In some specimens the 

 revolving and longitudinal lines are so distinct, particularly 

 the former, that the surface of the body whirl appears 

 covered with distinct square facets. Some naturalists con- 

 sider it only a variety of heterostropha. It differs in many important par- 

 ticulars from that species, but I regret that I have not been enabled yet 

 to examine the animal. [JUeKay.) 



Phi/sa charpentieri, KtJSTER. — Shell ovate-conic, semi-transparent, smooth, 

 shining, yell^^wish ; whirls five, flattened ; aperture oblique ; columella sub- 

 plicate, peristome thickened. 



Shell small, ovate conical, very transparent, shining, 

 smooth, dark yellow ; spire depressed conical, whirls 

 almost flat, scarcely separated by the suture, increasing 

 moderately. The body whirl decreasing in size toward 

 its base, which is like an inverted cone ; mouth yellowish, 

 tolerably wide, somewhat oblique ; outer lip arched, acute 

 and thickened within by a flesh-colored callus, which is 

 visible on the exterior as a bright yellow band ; columella 

 convex, with an elevated fold, which is thin, broad, and 

 sinuose. Height 4h, breadth 2j ; aper. 3'" long. 



Habitat. Baltimore: received by Mr. Bergrath v. Charpentier. (Kiister.) 



Fhysa charpen- 

 tieri, enlarged. 



Fig. 151. 



Physa philippi, KiJSTER. — Shell ventricose-ovate, acute, striate, shining, 

 diaphanous, yellowish horn color ; spire short, conoid, rather acute ; whirls 

 five, rapidly increasing, convex ; aperture elongate- 

 ovate ; columella concave ; white, peristome sharp, 

 with a ruddy band within. 



Resembling in its general appearance Physa hetero- 

 stropha, and in its straight axis and edge of the aper- 

 ture, yet there are diflferences enough to distinguish it 

 as a distinct species. The shell is ventricose, ovate, 

 thin, and almost transparent, with waving wrinkles 

 and yellowish horn-color. The apical whirls are rather 

 short, comprising almost one-third of the length of the 

 shell, increase rapidly in size, and are flattened convex, 

 with a somewhat deep suture ; body whirl ventricose ; 

 inner lip arched, rather wide ; mouth long, ovate, almost as broad as long ; 

 columella concave, white, arcuate, and separated by a sinus from the 



Phy/tn. philippi, 

 enlarged. 



