24 TESCRIPTION OF NEW 
Remarks.—Among the many shells from Georgia which I owe to the kindness of Major 
Le Conte, was a single specimen of this species. It is allied to UY. Lecontianus, (Nobis,) 
and is like it in outline; but it is more compressed, higher in the carina, and much more 
striate and rough on the exterior; it is also a thinner shell. The posterior margin of this 
specimen is also slightly emarginate. The tips of the beaks are not perfect, but they are 
enough so in this specimen, to show that the undulations are more numerous than usual 
and very beautiful. The upper portion of the double lateral tooth is very small in this 
specimen. 
Unto Moussontanus. Pl. XVIII. Fig. 22. 
Testa levi, ellipticd, subconvexd, subinequilaterali, posticé angulaté; valvulis percrassis ; natibus promi- 
nentibus, crassis 3 epidermide castaneo-fusca ; dentibus cardinalibus magnis, subcompressis ; lateralibus 
longis, crassis subcurvatus ; margarita argented et iridescente. 
Shell smooth, elliptical, subconvex, subinequilateral, angular before; valves very thick; beaks prominent and 
thick ; epidermis chestnut-brown; cardinal teeth large, rather compressed ; lateral teeth long, thick, somewhat 
curved; nacre silvery white and iridescent. 
Hab. Georgia, J. P. Barratt, M. D. 
My cabinet and cabinet of Dr. Barratt. 
Diam. 1.1, Length 1.8, Breadth 2.8 inches. 
Shell smooth, elliptical, subconvex, somewhat inequilateral, angular behind and rounded 
before; substance of the shell very thick, rather thinner behind; beaks prominent and 
thick; ligament rather long and thick; epidermis chestnut-brown, marks of growth distant 
and rather distinct; umbonial slope obtusely angular; cardinal teeth large, rather compressed, 
double in the left and single in the right valve; lateral teeth long, thick, laminate, thick- 
ened towards the posterior end and slightly arched; anterior cicatrices distinct ; posterior 
cicatrices distinct; dorsal cicatrices placed on the under side of the plate, near to the 
edge; palleal cicatrix impressed ; cavity of the shell not very deep; cavity of the beaks 
rather shallow and angular; nacre silvery white and iridescent. 
,Remarks.—The outline and general appearance of this species reminds one of U. delo- 
dontus, Lam. It is, however, a thicker shell and has thicker teeth. But three specimens 
were received by me. One of them is slightly tinged with salmon colour in the cavity 
of the beaks, and others may be found very likely more deeply coloured. 
I dedicate this species to Prof. A. Mousson, of Zurich, the author of “The Land and 
Fresh Water Shells of Java.” 
Unio nicerrimus. Pl. XVIII. Fig. 23. 
Testa levi, elliptica, subconverd, inequilaterali, posticée subrotundatd; valvulis subtenuibus; natibus parvis, 
prominulis, ad apices undulatis; epidermide nigra, nitidd, striatd; dentibus cardinalibus subcompressis, 
obliquis, acuminatis, crenulatis; lateralibus longis, lamellatis subcurvisques margarita alba et valde iridescente. 
Shell smooth, elliptical, rather convex, inequilateral, rounded behind; valves rather thin; beaks small, slightly 
prominent, undulated at the tip; epidermis black, shining, striate; cardinal teeth rather compressed, oblique, 
acuminate, crenulate ; lateral teeth long, lamellar and somewhat curved; nacre white and very iridescent. 
