26 NEW UMONID.E OF THE 



of the shell somewhat deep and rounded ; cavity of the beaks rather shallow and sub- 

 angular ; nacre pure white and very iridescent behind. 



Remarks. — -I have eight specimens of this small species before me. There were no 

 soft parts received. One of the specimens was quite young, but the beaks were too 

 much eroded to describe the undulations, which seem to be small and few. In. out- 

 line it is near to paulus, mix and Brumhyanus (nobis). It also reminds one of casta- 

 neus and Henleyanus (nobis), but it need not be confounded with either of the above. 

 Usually the whole disk is of a fine deep green, except the posterior slope, which is 

 yellow with two well marked rays on each valve. I know of no other species which 

 has these colors so well defined in this manner. Paulus has obscure rays on the pos- 

 terior slope somewhat like this. Some of the specimens have a little yellowness on 

 the anterior margin. One of them is so dark a green as to appear almost blackish 

 brown. A specimen in Mr. Mactier's cabinet is yellow over the disks except at two 

 lines of growth and on the posterior part, where there are three well defined dark 

 green rays on each valve. The two lai'gest specimens are one inch and three-tenths 

 wide. I have great pleasure in naming this after my young friend John Elliott, who 

 has already done much in making known the mollusca of his native state of Georgia. 



Uxvio CACAO. PL 5G, fig. 1G9. 



Testa Ifcvi, oblonga, subquadrata, compressa, ad latere planulata, postici^ obtuse angulata, injequilatcrali ; 

 valvulis subcrassis, antiee crassioribus ; natibus prominulis; epidermide castanea, superne micante, in- 

 ferne striata ; dentibus cardinalibus crassiusculis, striatis, suberectis, in utroque valvule duplieibus ; 

 lateralibus curtis, lamellatis rectisque ; margarita purpurascente et valde iridescente. 

 Shell smooth, oblong, nearly square, compressed, flattened at the sides, obtusely 

 angular behind and inequilateral ; valves somewhat thick, thicker before ; beaks a 

 little prominent; epidermis chestnut brown, shining above and striate below ; cardinal 

 teeth somewhat thick, striate, somewhat erect and double in both valves ; lateral 

 teeth short, lamellar and straight; nacre purjjlish and very iridescent. 

 Proc. Acad. Nat: Sci. 1859, p. 154. 

 Hah. — Chacktahachie River, West Florida. Major LeConte. 

 Cabinet of Major Le Conte. 

 Diam. -5, Length -9, Breadth 1-3 inches. 



Shell smooth, oblong, nearly square, comj)ressed, flattened at the sides, obtusely 

 angular behind, broadly rounded before, inequilateral ; substance of the shell some- 

 what thick, thicker before; beaks a little prominent; ligament very short, small and 

 light brown ; epidermis dark chestnut brown, shining above and transversely striate 

 below ; umbonial slope somewhat raised and rounded ; posterior slope narrow, raised 

 into a small carina, with two irregular, indistinct, impressed lines from the beaks to 

 the posterior margin on each valve ; cardinal teeth somewhat thick, striate, some- 

 what erect, crenulate and double in both valves ; lateral teeth sliort, lamellar and 



