70 PROCEEDINGS OF THE ACADEMY OP 



near the base, forming with the outer lip a broad, well defined canal at the 

 base. 



Length of shell 2 in. Breadth of shell 1| in. Length of aperture 1 in. 

 Breadth of aperture inch. 



Hab. Tennessee. My Cab.; Cab. Hugh Cuming, London; A. N. S., Phila- 

 delphia ; State collection, Abanv, N. Y. ; Smithsonian collection, Washing- 

 ton, D. C. 



06s. Another of the short, heavy forms in this genus, so unlike the normal 

 type of Io spinosa ; we think no one need confound it with any other species ; 

 its short, heavy, flattened spines jutting out like so many miniature spear 

 heads and its peculiarly twisted columella will readily characterize it. The 

 columella is also covered with a dense callous deposit, increased in thickness 

 at its upper part, and often blotched with dark red at that point ; irregular, 

 ill defined, but broad bands are seen in the interior, often faintly visible on 

 the epidermis. Appears to be a rather common species in some localities, of 

 which I possess some hundreds of specimens. 



Io inermis, Anthony. Shell couical, smooth, thick ; moderately elevated, 

 composed of 7 8 flattened whorls ; suture very distinct ; upper whorls slight- 

 ly coronated by an obscure row of low spines nearly concealed by the pre- 

 ceding whorl ; shell otherwise perfectly smooth or only occasionally or ob- 

 scurely nodulous on the body whorl ; lines of growth very strong and much 

 curved ; aperture pyriform, curved to the left, banded within ; columella 

 twisted, callous, thickened above ; sinus long and curved. 



Length of shell 2 1-16 in. Breadth of shell 1 in. Length of aperture 1 inch. 

 Breadth of aperture ^ inch. 



Hab. Tennessee. My Cab. ; Cab. Hugh Cuming, London ; A. N. S., Phila- 

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

 D. C. 



06s. Remarkable mainly for its plain, unadorned exterior and smooth 

 epidermis; its color is also lighter than " spinosa " or " fiuviatilis ". No 

 spines are visible on the body whorl of this species generally, but I have a few 

 specimens which may perhaps belong to it, and which have a few obscure 

 spines near the aperture ; these are, however, little more than knobs. Some 

 hundreds of this species have come under my notice. 



Io spirostoma, Anthony. Shell conical, broadly ovate, horn colored, 

 spinous : spines short, thick, seven to eight on each whorl ; whorls about 

 nine ; aperture ovate, about half the length of the shell ; columella and 

 outer lip much and regularly twisted, and forming a well defined sinus at 

 base. 



Length of shell If in. Breadth of shell \\ in. Length of aperture 15-16 in. 

 Breadth of aperture | inch. 



Hab. Tennessee. My Cab. and Cab. Hugh Cuming, London. 



06s. This is truly a most remarkable species of this highly interesting 

 genus of Mollusks ; its difference from the ordinary type of Io spinosa is too 

 marked to admit of its being confounded with that, or indeed any other 

 species ; its stout, ovate form, short, heavy spines, and, above all, the peculiar 

 and graceful curvature of its outer lip, are prominent characteristics and readily 

 distinguish it. Among several thousand specimens of Io in my possession, 

 but three adult individuals of this species have been noticed, although I have 

 a dozen or more which seem to be immature forms of it ; it may therefore be 

 considered as not only one of the most aberrant and beautiful forms of Io, 

 but also one of the rarest. 



Paludina lima, Anthony. Shell ovate, rather thin, dark green ; spire ob- 

 tusely elevated and composed of six convex whorls, which are strongly striate 

 or suboarinate ; sutures very distinct, and the upper part of each whorl being 

 flattened renders it more conspicuous ; aperture broad-ovate, about half the 



[Feb. 



