34 NEW UNIONID.i: OF THE 



right cardinal tooth to duplicature ; but it is slight and may not exist in all other 

 specimens. This species has some resemblance to exienstw (nobis) and naviculoides 

 (nobis) on one side, and vicinus (nobis) on the other, but it is not so transverse as the 

 two former, and is more so than the last. It also agrees in color of epidermis very 

 nearly with vicinus, but the lines of growth are not so distant, and they are better 

 defined. 



Unio satillaensis. pi. 27, fig. 9G. 



Testa IjEvi, elliptica, iiiflata, postice subbiangulata, vald6 inpcquilaterali ; valvulis suberassis, natibus 



prominulisj epidermide nigricante, minute transversa striata ; dentibus cardinalibus magnis, sub- 



compressis, elevatis, in utroque valvule duplicibus, crenulatis ; lateralibus longis, crassis subcurvisque; 



margarita purpurea et salmonis colore tineta et iridescente. 



Shell smooth elliptical, inflated, subbiangular behind, very inequilateral; valves 



rather thick ; beaks prominent ; epidermis blackish, minutely and transversely striate ; 



cardinal teeth large, somewhat compressed, raised, crenulate and double in both 



valves ; lateral teeth long, thick and somewhat curved ; nacre purple and salmon color 



and iridescent. 



Proc. Acad. Nat. Sci., 1858, p. 106. 

 Hah. — Satilla Kiver, Camden County, Georgia, T. C. Downie. 

 My cabinet and cabinet of Mr. Downie, Brunswick, Georgia. 

 Diam. 1-2, Length I'T, Breadth 3 inches. 



Shell smooth, elliptical, inflated, subbiangular behind, very inequilateral ; substance 

 of the shell rather thick ; beaks prominent; ligament short, thick and dark brown; 

 epidermis blackish, minutely and transversely striate, at the beaks shining; umbonial 

 slope raised into a rather high obtuse angle; posterior slope rather broad, carinate, 

 with a single raised line in each valve from the beaks to the posterior margin, disposed 

 to be -wrinkled ; cardinal teeth large, somewhat compressed, elevate, crenulate and 

 double in both valves ; lateral teeth long, thick, minutely corrugate and somewhat 

 curved ; anterior cicatrices distinct, rather small and well impressed ; jjosterior 

 cicatrices confluent and slightly impressed ; dorsal cicatrices placed under the plate 

 above the cavity of the beaks ; cavity of the shell rather deep and rounded ; cavity of 

 the beaks rather shallow and rounded; nacre purple and salmon color and very 

 iridescent. 



Soft parts. — Branchial utei-iis . No ova were found in the only two specimens 



received — they were probaljly males. BrancMcc large, thin, much rounded below, inner 

 one much the larger, free two-thirds the length of the abdominal sack. Palpi small, 

 thin, suboval, united half way down the posterior edges. Mantle thin, dark colored, 

 thickened and whitish at the edges, with numerous papillae below the branchial 

 opening. Branchial opening lai'ge, with, numerous brownish papillje on the inner 

 edges. Anal opening small, crenulate along the inner edges. Super-anal opening 

 large, colored on the border and united below. Color of the mass whitish. 



