LniN.EA. 473 



nal of the Academy of Natural Sciences," ii. 167, as " L. columella^ 

 var. a. small, black, from Cold Water Creek, Missouri." 



The form called LimncEa macrosloma is thus described in the 

 first edition. Tig. 148 : — 



Shell fragile, pellucid, light horn colored, ovate-conical; last 

 whorl very large, moderately inflated, surmounted by three very 

 small, oblique ones, ibrming an acute apex ; surface shin- 

 ing, marked by fine lines of growtli, which are crossed 

 and rendered flexuous by numerous revolving lines, faintly 

 visible without a magnifier ; suture distinct, the whorls 

 api)roaching it by a gradual sloj^e ; aperture ovate, very 

 ample, four fifths the length of the shell, and, when ma- 

 ture, broadly expanded ; outer lip very sharp and thin, 

 broadly rounded in front, and maintaining its sharp edge, 

 it rises and disappears within the shell ; pillar so broadly arched 

 as to allow a view of nmch of the interior of the spire ; a minute 

 uml)ilicus is formed by a reflected scale of enamel ; in mature shells 

 a glazing of enamel is found upon the preceding whorl as it en- 

 croaches upon the aperture. Length, eleven twentieths of an inch ; 

 breadth, seven twentieths of an inch ; divergence, seventy-three 

 degrees. 



Found at New Bedford by IMr. Shiverick. Much larger s])eci- 

 niens were obtained by Colonel Totten, at Tiverton, Rhode Island. 

 Dr. Binney found it also in Vermont. 



This shell is closely allied to L. columella^ and in an immature 

 state is not easily distinguished from it ; but that shell is much 

 more elongated, and regularly tapering, the divergence of the spire 

 l:)eing not more than sixty degrees. Such specimens Professor 

 Adams described as his L. acuminata. But at maturity the shell 

 is very distinctly characterized by its widely sjireading outer lip, 

 which gives great expansion to the aperture. Mr. Say received it 

 from the rice-fields of Carolina. It is the analogue of the L. ovata 

 of Europe. 



Limnaea decoUata. 



Shell ventricose, rather thick, olivaceous-green color; Avhorls two to three, 

 body whorl composes almost the whole shell ; aperture very large, sub-campanu- 

 late ; columella-fold very prominent. 



Limncvn dccoUata, Mighet.s, Froc. Bost. Soc. i. 49 (1841) : Bost. Journ. iv. 4-5, 3.36, pi. 

 4, fig. 13 (ami Adams) (1842). — W. G. Binney, Smith. Inst. L. and Fr. W. Shells, 

 ii. 31, figs. 36, 37 (1865). 



