14 DESCRIPTION OF NEW 



Unio rufusculus. pi. XIV. Fig. 7. 



TcsU'i ftPvi, elliplicn, stibcompressii, inxriitllaleraU, postice biangulatu ; valvidis siihcrasstbvs : nttllbus sub- 

 jiromlnmlibus ; epUlermuh tenebroso-J'vsca, st riatc'i : detillbits cardinulibus nbluinis, parvis slrlalisque ; lulerali- 

 bus remolis, longis, lamellatis, rectis; margaritd vel alba vel salmonis colore linctd. 



Shell snioolli, elliptical, rather compressed, inequilateral, biaiigular behind; valves rather thick ; bealis some- 

 u- hat prominent; epidermis dark-brown, striate; cardinal teeth oblique, small and striate; lateral 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 somevvhat prominent and 

 submcdial; 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 string; 

 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. complanalits is 

 the type. It seems to stand between it and U. Congarceus, (Nobis.) It is more angular 

 on the umbonial slope than complunatus, and less so than CongarcBus. 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 platii/ateris, 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.ftihnis, (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 o( fulvus. 



Unio Whiteianus. PI. XIV. Fig. 8. 



Testa Itrvi, elliplicd, hijlaiu, valde insequilateruli, postice subangitlatd ; vahulis crassis; natibus siibpromi- 

 nentibus; tpidermide vel tencbroso-fusca vel nigra, striata, ad apices polild ; dentibus cardinulibus magnis, 

 elevatis, crenulatis; lateralibus longis subcurvisque ; margaritd vel albd vel salmonis colore tincta. 



Shell smooth, elliptical, inflated, very inequilateral, snbangnlar 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. Rev. 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 



