474 lijin^idj:. 



Limn(tus catascoplum, Hai.demax, part, Mon. 52, pi. 14, fip:s. 1 -3 (1842). 

 Liiivums decollatas, Kustei;, in Chejin. 2d ed. 45, pi. 8, figs. 11-14. 



Shell very ventricose, rather tliick, sub-ovate or sub-rotund, in 

 outline an irregular rhomboid ; epidermis of an olivaceous-green 

 color, rather thin, deciduous ; ■\vhorls two to three ; spire 

 very short, generally decollated ; whole surface gen- 

 erally rather rough ; striae of growth coarse and fine 

 alternately ; transverse strias on the body whorl sparse, 

 interrupted, sometimes obsolete ; body wliorl composes 

 almost the whole shell ; aperture very large, sub-cam- 

 panulate ; its length is very little greater than the 



L. decollata. "". ^ • ^ l^ ^ ji 



breadth, and occupies more than two thirds the length 

 of the shell ; labrum rather thin, simple ; fold of the columella very 

 prominent. Length, six tenths of an inch ; breadth, five tenths of 

 an inch ; height, four tenths of an inch. 



Animal dingy mouse-color, with a slight tinge of pur^jle, covered 

 with numerous microscopic, elongated white spots on every visible 

 part of the surface, including the mouth and tentacula ; foot of a 

 chocolate color, rather broad, length rather greater than the aper- 

 ture ; habits sluggish. Cabinets of the Bost. See. N. H., Dr. Gould, 

 S. S. Haldeman, J. G. Anthony, J. W. Mighels, and C. B. Adams. 



Unity, Maine, discovered by Dr. Milliken of that town, to whom 

 we are indeljted for specimens. 



This odd but interesting shell is readily recognized by its rliom- 

 boidal aspect, wide aperture, and rather rough and distorted appear- 

 ance. It is allied to L. catascopiuin, Say, but is distinct from that 

 shell by having less whorls by two, and a much shorter spire ; by 

 l)eing wider, and its divergence greater by more than thirty degrees. 

 By some it has been supposed to be identical with L. emarginata, 

 Say. This is impossible. L. emargimta is much more cylindrical, 

 the divergence of its spire is scarcely half as great as that of our 

 shell ; it is much thinner, and has at least two more volutions. Our 

 shell is also destitute of the " deep emargination " which distin- 

 guishes L. cmari^nnata. (Mig-Jtc/s and Adams.) 



Pound around Lake of the Woods, in Maine and Connecticut. 



Limnsea ampla. 



Shell large, inflated, sub-oval, ratlier thin, obseure olivaceous-green color ; whorls 

 five, convex ; suture deep ; aperture oblong, occupying rather more than two 

 thirds the length of the shell; columella-ibld very prominent; umbilicus open and 

 very deep. 



