Description of some new Shells. 269 



rior confluent, dorsal situated horizontally across the cavity of the 

 beaks and distinct ; cavity of the beaks shallow and rounded ; 

 nacre white, slightly iridescent over the entire surface of the 

 valve, with faintly impressed strias or rays diverging from the 

 cavity of the beaks, and extending to the basal margin. Inhab- 

 itant unknown." 



The above description is by Doct. Charles J. Ward, of Roscoe, 

 Ohio. 



"■ Paludina heterostropha, Kirtland. Plate III. Fig. 2. 



Sinistral, aperture more than half the length of the shell. 



Shell sub-globose, ovate ; spire depressed, apex generally trun- 

 cate ,• whorls five ; aperture ovate, with its superior extremity 

 curved towards the body whorl, within bluish wiiite ; epidermis 

 greenish horn color, usually coated with ferruginous clay. Length 

 three quarters of an inch. 



This shell frequently occurs in Mill and Yellow creeks, tribu- 

 taries of the Mahoning river. 1 formerly considered it a mere 

 variety of the P. decisa of Say ; but on further examination find 

 it to be specifically distinct. It never attains more than half the 

 length of that species ; its spire is never depressed, and it is al- 

 ways heterostrophal." 



I am indebted to Doct. J. P. Kirtland for the foregoing de- 

 scription. 



Physa Sayii, 7iohis. Plate III. Fig. 3. 



Shell sinistral, ovate ; color brownish yellow, or chestnut ; 

 whorls five ; the first large, the others small, terminating in an 

 acute dark brown apex ; aperture large, four fifths of the length 

 of the shell ; translucent ; length one inch, breadth seven tenths 

 of an inch. 



I first found this shell, May, 1837, in a small lake called Lake 

 Pipin, which is situated about fifty rods from the Cuyahoga river, 

 in Franklin township. Portage county, Ohio, (the same locality 

 where was found the Anodonta Pipiniana of Lea.) All the shells 

 of this species hitherto found were dead, although much time was 

 spent in examining for live ones in May, 1837, and in June, 1838. 

 A few only were found, and are in the cabinets of Mrs. Saj'', 

 Doct. Kirtland, Doct. Ward, and myself. 



