14 DESCRIPTION OF NEW 
Umio ruruscunus. Pl. XIV. Fig. 7. 
Testa levi, ellipticd, subcompressd, inxquilaterali, posticé biangulatd ; valvulis subcrassibus ; natibus sub- 
prominentibus ; epidermide tenebroso-fuscd, striata ; dentibus cardinalibus obliquis, parvis striatisque; laterali- 
bus remolis, longis, lamellatis, rectis; margarita vel alba vel salmonis colore tinctd. 
Shell smooth, elliptical, rather compressed, inequilateral, biangular behind; valves rather thick; beaks some- 
what prominent; epidermis dark-brown, striate; cardinal teeth oblique, small and striate; Jateral teeth remote, 
long, lamellar and straight; nacre white or salmon coloured. 
Hab. Abbeville District, S.C. J. P. Barratt, M.D. 
My cabinet. 
Diam. .9, Length 1.4, Breadth 2.4 inches. 
Shell smooth, elliptical, rather compressed, inequilateral, biangular behind, rounded 
before, substance of the shell rather thick, thicker before; beaks somewhat prominent and 
submedial ; ligament rather long and thick; epidermis dark-brown, obscurely rayed on the 
posterior slope, striate towards the margin, with obscure, nearly equidistant marks of 
growth; umbonial slope subangular; cardinal teeth oblique, small, with regular strie; 
single in the right and double in the left valve; lateral teeth separated from the cardinal 
tooth, long, lamellar, straight, and slightly thickened towards the posterior end; anterior 
cicatrices distinct; posterior cicatrices confluent; dorsal cicatrices placed rather above 
the centre of the cavity of the beaks; cavity of the shell rather shallow; cavity of the 
beaks very small; nacre white or salmon coloured. 
Remarks.—This species belongs to the group of which the common U. complanatus is 
the type. It seems to stand between it and U. Congareus, (Nobis.) It is more angular 
on the umbonial slope than complanatus, and less so than Congareus. Of the three speci- 
mens received, two are salmon coloured. The oldest specimen is very thick and much 
eroded. The youngest is rather thin. The outline of this species is very much like the 
figure of Unio planilateris, Conrad, but it differs in the colour of the epidermis, in the 
thickness of the teeth, and the obliqueness of the umbonial slope. It is also very like 
U. fulvus, (Nobis,) which also came from South Carolina; and it is possible that when 
good suites are brought together, this species may prove to be only the adult of a flatter 
variety of fulvus. 
Unio Wuireianus. Pl. XIV. Fig. 8. 
Testa levi, elliptica, inflata, valde inxquilaterali, posticée subangulatd ; valvulis crassis; natibus subpromi- 
nentibus; epidermide vel tenebroso-fusca vel nigra, striata, ad apices polité; dentibus cardinalibus magnis, 
elevatis, crenulalis ; lateralibus longis subcurvisque; margarita vel alba vel salmonis colore tincta. 
Shell smooth, elliptical, inflated, very inequilateral, subangular behind; valves thick; beaks somewhat promi- 
nent; epidermis dark-brown or black, striate, towards the beaks polished; cardinal teeth large, elevated, crenu- 
lated; lateral teeth long and somewhat curved ; nacre white or salmon coloured. 
Hab. near Savannah, Geo. Rey. G. White. 
My cabinet and cabinet of Mr. White. 
Diam. .1, Length 1.4, Breadth 2.5 inches. 
Shell smooth, elliptical, inflated, very inequilateral, rounded before, subangular behind; 
substance of the shell thick; beaks somewhat prominent; placed towards the anterior 
ss 
