48 NEW UNIONID^, MELANID^, ETC.. 



Remarhs. — I have a number of females as well as males before me. Unfortunately 

 none were received with the soft parts. It is of the group to which Stewardsonii 

 (nobis) belongs, and is nearly allied to that species, but cannot be confounded with 

 it. It is much smaller, has two emarginations and two angles on the umbonial 

 slope, neither of which characters belong to Stewardsonii. But like it the female en- 

 largement is at the basal termination of the lateral furrow, and in some females it is 

 quite large and generally of a dark green. It protrudes beyond the basal emargina- 

 tion. The rays which usually extend over the whole disk are broad anteriorly and 

 capillary posteriorly. None of the specimens had beaks perfect enough to give the 

 character of the undulations. The female is figured. 



Unio granulatus. pi. 16, fig. 46. 



Testa plicata, elliptica, subinflata, valde insBquilaterali, postice obtuse angulata, antice rotunda ; valvulis 

 subtenuibus, antice aliquanto crassioribus ; natibus prominulis, ad apices undato-granulatis ; epider- 

 mide tenebroso-oliva, eradiata, transverse striata ; dentibus cardinalibus parvis, compressis, obliquis, 

 crenulatis, in utroque valvule duplicibus ; lateralibus longis, acicularis, tenuis subrectisque ; marga- 

 rita purpurescente et valde iridescente. 



Shell folded, elliptical, somewhat inflated, very inequilateral, obtusely angular be- 

 hind, round before ; valves rather thin, slightly thicker before ; beaks a little promi- 

 nent, undulate and granulate all over ; epidermis dark olive, without rays, trans- 

 versely striate; cardinal teeth small, compressed, oblique, crenulate and double in 

 both valves ; lateral teeth long, acicular, thin and nearly straight ; nacre purplish 

 and very iridescent. 



Proc. Acad. Nat. Sci., 1861, p. 60. 



Eah — Big Prairie Creek, Alabama, E. R. Showalter, M. D. 



My cabinet and cabinet of Dr. Showalter. 

 Diam. -45, Length -62, Breadth I'lO inches. 



Shell folded, elliptical, rather inflated, very inequilateral, obtusely angular be- 

 hind, sulcate and round before ; substance of the shell rather thin, slightly thicker 

 before ; beaks a little prominent, undulated granulations all over ; ligament very 

 small, thin and light brown ; epidermis dark olive, without rays, transversely 

 striate below, and with distant lines of growth ; umbonial slope inflated and 

 rounded; posterior slope narrow elliptical, very slightly raised, with two obscure 

 yellowish rays on each valve; cardinal teeth small, compressed, oblique, crenulate, 

 double in both valves; lateral teeth long, acicular, thin and nearly straight; 

 anterior cicatrices* distinct, rather large and well impressed ; posterior cicatrices 

 confluent, rather large and very slightly impressed ; dorsal cicatrices placed over the 

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



