26 NEW UNIONID^, MELANID^E, ETC., 



rounded and somewhat sulcate before ; substance of the shell thin, slightly thicker 

 before; beaks prominent, swollen, with two series of undulations which form two 

 rows of nodes ; ligament rather long, narrow and light brown ; epidermis polished, 

 yellowish green or brownish, obscurely radiated or without rays, with two or three 

 very distant lines of growth; umbonial slope raised and rounded; posterior slope 

 elliptical, rather broad, with three brownish lines from the beaks to the margin on 

 each valve ; anterior cicatrices confluent, large and very slightly impressed ; posterior 

 cicatrices confluent, very large and very slightly impressed ; dorsal cicatrices placed 

 over the centre of the cavity of the beaks ; cavity of the shell deep and wide ; cavity 

 of the beaks rather deep and rounded ; nacre bluish white and very iridescent. 



Remarlis. — Nearly a dozen specimens were brought by Lieut. Beale, the largest of 

 which are about four inches wide. In outline it is very nearly the same with Ges- 

 neri (nobis), but it is not so large or heavy, that shell being sometimes as wide as 

 7J inches. It differs also in the epidermis, the Gesneri being usually yellow and the 

 nacre thicker. The Leonetisis reminds one of Benedictii (nobis,) and Footiana (nobis;) 

 but it is not winged like the former, and it differs from the latter in being more 

 medial, and iu the marks of growth being fewer and more distant. It cannot be 

 confounded with Steioartiana (nobis), a Louisiana species, for that is much more 

 inflated and is not so transverse. The epidermis of the young specimens are greenish, 

 while the old ones are a dusky brown. 



Anodonta Bealei. PL 9, fig. 25. 



Testa laevi, ovato-oblonga, subinflata, inasquilaterali, postioe subbiangulata, antice rotundata ; valvulis 

 tenuibus ; natibus subprominentibus, ad apices undulatis ; epidermide olivacea, polita, obsolete radiata ; 

 margarita caeruleo-alba et iridescente. 



Shell smooth, ovately oblong, somewhat inflated, inequilateral, subbiangular behind, 

 rounded before ; valves thin ; beaks somewhat prominent, undulate at the tips ; 

 epidermis olivaceous, polished, obscurely rayed ; nacre bluish white and iridescent. 

 Proc. Acad. Nat. Sci., 1863, p. 194. 



Hah. — Leon County, Texas, Lieut. Beale ; Verdigris River, Texas, Mr. F. Hawn. 



My cabinet and cabinet of Smithsonian Institution. 

 Diam. 1-3, Length 1-7, Breadth 3-2 inches. 



Shell smooth, ovately oblong, somewhat inflated, inequilateral, subbiangular be- 

 hind, rounded before ; substance of the shell thin ; beaks somewhat prominent, un- 

 dulate at the tips and forming two rows of granules; ligament rather long, thin, 

 brown ; epidermis olivaceous, obscurely rayed, polished, with two or three distant 

 marks of growth ; umbonial slope regularly rounded ; posterior slope rather narrow, 

 somewhat flattened, with three indistinct rays from the beaks to the posterior margin 

 on each valve ; posterior cicatrices large and confluent ; anterior cicatrices large and 



