NATURAL SCIENCES OF PHILADELPHIA. 71 



length of the shell, livid within ; c >lumella slightly rounded and callous 

 deposit small ; umbilicus none. 



Length \\ inches. Breadth J inch. 



Hab. South Carolina. My Cab.; Cab. H. Cuming, London; A. N. S.. 

 Philada. ; Smithsonian collection, Washington, D. C. 



Obs. In general form not unlike our We stern P. Integra, Say, from which 

 it differs, however, by its revolving, raised strise and by its carina, which are 

 also well developed ; the lines <>f growth are very strong, and decussating with 

 the stria give the surface a beautifully rough appearance, which suggests its 

 specific name. It is really one of our handsomest species, and so unlike all 

 others that no American species can readily be mistaken for it. In most speci- 

 mens the body whorl is very strongly carinate about the middle, and the outer 

 lip is considerably produced as in P. subsolida, nob. 



Paludina decapitata, Anthony. Shell globular, thin, of a light green color ; 

 spire truncate, but never elevated under any circumstances, composed of 

 about four very flat whorls ; aperture broad, ovate, one-half the length of the 

 shell, within dusky white ; columella regularly but not deeply rounded, with a 

 slight deposit of callous, and having a very small linear umbilicus at base. 



Hab. Tennessee. My Cabinet. 



Obs. A single specimen only is before me, and therefore I claim it as a new 

 species with some hesitation ; it seems to me, however, too unlike any of the 

 ordinary forms in this genus to warrant its being included with any of them ; 

 it is the most globose of any species hitherto published, if we except the small, 

 round forms which were long since removed, and very properly too, to Amni- 

 cola ; the spire is entirely wanting, but traces of the sutures show the number 

 of whorls ; and its present appearance forbids the idea of its ever having had 

 an elevated spire. 



Paludina humerosa, Anthony. Shell ovate, thick, bright green, imper- 

 forate ; spire rather obtusely elevated, composed, of about 5 6 convex whorls : 

 upper whorls smooth, body whorl and preceding one strongly striate and 

 granulate or subgranulate ; sutures very distinct ; aperture ovate, nearly one- 

 half the length of the shell, livid within. 



Length about half an inch. 



Hab. Alabama. My Cabinet. 



Obs. A single specimen only is before me, but it is sufficiently distinct ; its 

 granulated surface and the broad shouldering of the whorls are it- 1 chief char- 

 acteristics ; compared with P. genicula, Con., it is more slender, darker in color, 

 and its granulated surface is of itself a sufficient distinction. 



Paludina exilis, Anthony. Shell turrited, smooth, rather thick ; color 

 light apple green ; spire elevated, composed of about seven volutions ; suture 

 well marked ; aperture small, broad-ovate, livid within ; body whorl distinctly 

 angulated, subumbilicate, and with very distinct lines of growth ; columella 

 well rounded and curved with a callous deposit, connecting perfectly with the 

 outer lip thus forming a continuous rim. 



Length 1\ inches. Breadth f inch. 



Hab. Mississippi. My Cab. ; Cab. H.' Cuming, London; A. N. S., Phila- 

 delphia ; State collection, Albany, N. Y. ; Smithsonian collection. 



Obs. One of the most slender of our American species ; Paludina subsolida, 

 nob., is more ponderous, more globose, and has a larger aperture ; no other 

 species approaches it in general appearance ; the whorls of this species taper 

 more rapidly to an acute apex than in most of the species ; compared with P. 

 Integra, Say, it is more slender, more solid, and the aperture is much smaller. 



Paludina subsolida, Anthony. Shell ovate, imperforate, very thick ; co'or 

 light green, verging to brown in old specimens ; spire much elevated, com- 

 posed of 6 7 inflated whorls ; sutures very distinct ; aperture broad-ovate, 



I860.] 



