46 DESCRIPTION OF NEW 
much broader. In colour they are entirely different One is white, the other salmon- 
coloured. The fosset at the end of the ligament is remarkably large and curved. 
This beautiful species I dedicate to the memory of the great master in natural science, 
Linneus. 
Anoponta osuita. PI. XXVIII. Fig. 52. 
Testa levi, ellipticd, compressa, inequilaterali, postice subbiangulatd; valvulis pertenuibus; natibus 
prominulis, ad apices undulatis ; epidermide nitidd, bruneo-viridi, obsolete radiata; margarita cerulea alba 
et iridescente. 
Shell smooth, elliptical, compressed, inequilateral, subbiangular behind; valves very thin; beaks slightly 
prominent, undulated at the tip; epidermis shining, brownish-green, obscurely radiated; nacre bluish-white and 
iridescent. 
Hab. Campbell county, East Tennessee, President Estabrook. 
My cabinet and cabinet of President Estabrook. 
Diam. .7, Length 1.2, Breadth 2 inches. 
Shell smooth, elliptical, compressed, inequilateral, subbiangular behind, rounded before 
and slightly flattened on the anterior portion of the disk, with a simple curved dorsal line; 
substance of the shell very thin; beaks very small, slightly prominent and undulate at the 
tip; ligament rather thin and not very long; epidermis shining, brownish-green, obscurely 
rayed, with rather distant marks of growth; posterior slope rather narrow and some- 
what compressed, with three distinct and somewhat distant green rays from the beaks to 
the posterior margin; umbonial slope rounded and considerably raised; anterior cicatrices 
confluent; posterior cicatrices confluent; dorsal cicatrices on the inside of the dorsal line; 
cavity of the shell very shallow; cavity of the beaks very shallow; nacre bluish-white 
and iridescent. 
Remarks.--I received but three specimens from President Estabrook of this species. 
The largest, although small, seems to be adult. The green colour of the posterior por- 
tion of the valve is dark and fine. There are here three rather broad and unusually dis- 
tinct rays, the inferior one being the largest, and well over the umbonial slope. ‘The 
anterior portion of the disk is darker and brownish. This species is perhaps the nearest 
allied to An. denigrata, herein described. It may be distinguished by its being more 
compressed, greener and smaller. 
Anoponta virens. PI]. XXVIII. Fig. 53. 
Testa levi, ellipticd, ventricossissima, inequilaterali, posticée subangulata; valvulis tenuibus; natibus 
prominentibus, valdé tumidis, ad apices rugoso-undulatis; epidermide viridi, politd, obsolete radiala; mar- 
garita alba et iridescente. 
Shell smooth, elliptical, very much inflated, inequilateral, subangular behind; valves thin; beaks prominent, 
very much swollen and rugosely undulate at the tip; epidermis green, polished, obscurely radiated; nacre white 
and iridescent. 
Hab. Red river, at Alexandria, Louisiana, J. Hale, M. D. 
My cabinet and cabinet of Dr. Hale. 
Diam. 1.9, Length 2.3, Breadth 3.5 inches. 
