84 NEW-YORK FAUNA — MOLLUSCA. 



Paludina DISSCISA. 



PLATE VI. FIG. 131. A. B. —PLATE VII. FIG. 134. 



(STATE COLLECTION.) 



Paludina dxisa. Say, Nich. Ency. pi. 2, fig. 6. Am. Conch, pi. 10. 



P. ponderosa. DESHAYB3 in Lam. (Young.) 



P. decisa. Adams, Am. Jour, of Science, Vol. 40, p. 266. 



P. id. Gould, Invertebrata of Mass. p. 227; fig. p. 14-4. 



P. id. Haldeman, Monograph, p. 1, pi. 1. 



Description. Shell ovate, elongate, thick and robust, often truncated at the apex. Whorls 

 four to five, with minute transverse strias and revolving lines, rounded, and briefly turning 

 into the suture, which is distinctly impressed. Aperture subovate, entire, and forming an 

 angle above. Lip simple, but forms a rounded margin as it rises towards the columella. 

 Opercle coriaceous, thin, concentrically striate. 



Color. Dark olive green. Aperture bluish white. Animal : Foot soiled olive, varied with 

 orange ; tentacles olive, spotted with orange. 



Length, 1*0. Diameter, 0'7. 



This is the most common species in this State, and found in most of the ponds and slug- 

 gish streams. The name originally given to it by Say, is evidently a misprint for disscisa. 



Paludina Integra. 



PLATE VII. FIG. 132. a. youno ; b. adult. 



(STATE COLLECTION.) 



P. inlegra. Say, Journ. Acad. Nat. Science*, Vol. 2, p. 176. 

 P. id. Haldehan, Monograph, etc. p. 10, pi. 3. 



Description. Shell rather solid, conic. Whorls six, wrinkled across. Spire rather elon- 

 gated, entire at the apex. Suture profoundly indented. Aperture subovate, rather more than 

 half the length of the shell. 



Color. Light olive green, tinged with rufous ; the callus margined with blackish. 



Length, l'l ; of aperture, 0"5. 



Mr. Haldeman has given an excellent figure of this species, which was first described by 

 Say from immature specimens collected in Missouri. The shells which are represented on 

 the plate, were obtained from the River Hudson near Albany : they are among the largest 

 measured. Farther south they appear to be larger still : the young shells, five-tenths of an 

 inch long, are more globose. Mr. Cozzens has favored me with specimens from the River 

 Passaic, which I refer to this species. They were obtained two miles and a half below the 

 Acquaconock church. The Passaic here flows over a sandstone bed, highly charged with 

 iron ; the shells are more rufous and ponderous. In the adult, an obsolete carina on the 



