330 New Fresh-Woater Shells. 
elevated and acute, and A. fluviatilis, Drap., has the 
apex more prominent and nearer one extremity. 
CycLAS ELEGANS. 
Plate III. Fig. 11. 
' C. testa bizonatá, subglobos’, rhombico-orbiculari, equilaterali, ele- 
ganter et tenuissimé striatà ; natibus haud es umbonibus 
tenuibus ; intis albido-cerulescente. 
Shell sub-globular, rhombic-orbicular, equilateral, 
finely and'elegantly striated, with a horny green epi- 
dermis, with a straw-colored marginal zone, of varia- 
ble width, and another of the same color, and usually 
much narrower, and about equidistant between the 
margin and the beak, but varying somewhat in posi- 
tion; beaks not prominent, slightly undulate, central, 
not decodes’ umbones very thin; within bluish 
white ; lateral teeth strongly deldi, cardinal teeth 
Bisdigretitery: The young shell has -— a marginal 
zone, and is less inflated. 
. Length, .43 inch; height, .36 inch ; width, .26 
inch. ‘eh 
Habitat and station. This species was discover- 
ed by Mr. Kinne Prescott, in a swamp, in Wey- 
bridge, Vt. This swamp nearly surrounds an old 
Indian encampment, and is impassable. | A con- 
siderable number of specimens Were obtained is 
some difficulty and hazard. "The species has ! 
found at Burlington, TE C 
. Cabinets of Bost. Soc. Nat. Hist. ; of Middlebury 
College ; of Dr. A. A. Gould ; of Messrs. Kinne Pres- 
cott and Luther H. Sheldon, of. Andover; and my ow?- 
Remarks. This shell is remarkable for its d 
