FRESH WATER AND LAND SHELLS. 281 
Shell oblong, inflated on the umbonial slope, which is rounded ; substance of the shell 
very thin, thicker before; beaks rather prominent; ligament rather long and thin; epi- 
dermis yellow, inclining to saffron, with rather numerous indistinct green rays, more 
dense on the posterior portion; cardinal teeth small, tuberculate, single in the right and 
double in the left valve; lateral teeth long, thin, and somewhat curved; anterior cicatrices 
confluent; posterior cicatrices confluent; dorsal cicatrices placed under the cardinal tooth; 
eavity of the shell deep and rounded; cavity of the beaks shallow and angular; nacre 
somewhat golden-coloured and very iridescent. 
Remarks.—A siugle specimen of this shell was given to me last winter by Dr. Budd, 
of New York, and I have delayed the description in the hope of having others for com- 
parison. In its exterior form and appearance, it resembles the Margaritana marginata 
—but its teeth at once distinguish it from that species. The cardinal teeth are remark- 
ably small, being little more than tubercles. 
Unio suprersys. Pu. 42. Fie. 11. 
Testa alatd, triangulari, valde inflata, valdé inequilaterali; valvulis subcrassis; natibus elevatis; epidermide 
tenebroso-fuscd; dentibus cardinalibus perlongis lamellatisque ; lateralibus longis, lamellatis curvisque ; margarita 
aurea et valde iridescente. 
Shell winged, triangular, very much inflated, very inequilateral ; valves rather thick ; beaks elevated ; epidermis 
dark-brown ; cardinal teeth very long and lamellar; lateral teeth long, lamellar, and curved; nacre golden and very 
iridescent. 
Hab. New Holland. J.C. Jay, M.D. 
My cabinet and cabinet of Dr. Jay. 
Diam. 1.9, Length 3. Breadth 8.6 inches. 
Shell winged, triangular, very much inflated, very inequilateral ; substance of the shell 
rather thick, thinner behind; beaks elevated, rounded; ligament very long and rather 
thin; epidermis dark-brown, with three obscure rays on the posterior slope; cardinal 
teeth very long, double in the right and séngle in the left valve ; lateral teeth long, lamel- 
lar, and curved; anterior cicatrices confluent; posterior cicatrices confluent; dorsal cica- 
trices nearly concealed under the plate between the cardinal and lateral teeth; cavity of 
the shell very deep and rounded; cavity of the beaks very deep and angular; nacre pale 
golden, brilliant, and iridescent. 
Remarks.—I owe to the kindness of Dr. Jay the possession of this beautiful and rare 
Unio. Several of its characteristics are very remarkable; its long cardinal teeth being 
reversed, the double one being in the right valve and the single one in the left. The 
nacre is unusually rich and splendid. The beaks of the specimen before me are eroded, 
but they are perfect enough to observe that the tips must have been thickly set with 
minute undulations, probably radiating and not concentric. In outline, it has some 
resemblance to Unio purpuratus, (Lam.,) but is more triangular and more inflated. 
Dr. Jay received this species from a correspondent in New Holland, accompanied with 
the Unio delphinus, (Nobis.) The latter species does not, however, i believe, exist on 
that island, but on the coast of Malacca, in the river Souzi, the locality given to me 
when I described it being erroneous. 
