ee 
FRESH WATER AND LAND SHELLS. Zr 
Remarks.—This is an interesting species, rather smaller than the U. parvus, (Barnes,) 
and very closely resembling it in most of its characteristics. Like it, the epidermis is 
dark and roughly striate. It differs in form in not being transverse, but inclining to be 
obovate—also apparently being devoid of the singularly beautiful undulations of the 
beaks of the parvus. Iam not, however, positive on this subject, as the three specimens 
submitted to my examination are all slightly eroded at the beaks. The position and form of 
the dorsal cicatrices differ. In the parvus they form a row across the cavity of the beaks. 
On a close examination of the region of the anterior cicatrices, may be observed a third 
distinct cicatrix, placed on the side of the anterior portion of the cardinal tooth, Nearly 
the same position of a cicatrix was observed and described in the U. cucwmoides, (Nobis. ) 
Trans. Am. Phil. Soc., vol. viii. p. 193. 
Unio ruscatus, Pr. 40. Fie, 4. 
Testa ellipticd, subinflatd, valde inequilaterali, postice biangulatd; valvulis tenuibus; natibus vix prominentibus; epidermide 
tenebroso-fuscd, obsolete radiatd; dentibus cardinalibus parvis; lateralibus sublongis subrectisque; margaritd cupred. 
Shell elliptical, rather inflated, very inequilateral, biangular behind; valves thin; beaks slightly prominent ; epider- 
mis dark-brown, obsoletely radiated; cardinal teeth small; lateral teeth rather long and nearly straight; nacre 
copper-coloured, 
Hab. Black Creek, Florida. S. B. Buckley. 
My cabinet and cabinets of Dr. Budd and Mr. Buckley. 
Diam. .5, Length .9, Breadth 1.7 inches. 
Shell elliptical, rather inflated, very inequilateral, biangular behind; umbonial slope 
subangular; valves thin; beaks slightly prominent; ligament rather short and thin; epi- 
dermis dark-brown—with numerous small obscure green rays, more distinct on the 
umbones; cardinal teeth small, disposed to be double in both valves; lateral teeth rather 
long, thin, and nearly straight; anterior cicatrices distinct; posterior cicatrices confluent; 
dorsal cicatrices placed under the anterior of the lateral tooth, Cavity of the shell rather 
shallow; cavity of the beaks small and subangular. Naere copper-coloured and iridescent. 
Remarks.—This species somewhat resembles Unio pustllus, (Nobis,) but may at once 
be distinguished by the absence of the sharp angle of the umbonial slope of that shell, 
and the distinct angle of its posterior margin.—It differs also in the colour of the nacre. 
The fuscatus is dark on the posterior slope, and compressed at the posterior portion of the 
shell. ‘The minute rays, which are nearly lost in the dark hue of the epidermis, are 
closer and more distinct towards the beaks. Neither of the three specimens before me 
are perfect at the beaks, and I am therefore unable to say whether the tips are undulated 
in this species. 
Unio Buppianus, Pu. 40. Fra. 5. 
Testa oblonga, compressd, inequilaterali, postice subbiangulatd; valvulis subcrassis; natibus subprominentibus; head ig 
F ener ie od : m ‘ s ‘ 4 “ " Pere . A et tridesces 
subnigrd; dentibus cardinalibus magnis lamellatisque; lateralibus perlongis subrectisque; margarita purpurea et tridescente. 
Shell oblong, compressed, inequilateral, subbiangular behind; valves rather thick; epidermis almost black; car. 
dinal teeth large and lamellar; lateral teeth long and nearly straight; nacre purple and iridescent, 
