New species of Fresh Water Shells. * ge 
pressed ; anterior muscular i ernnn prauada paniasiee one slight- 
ly impressed ; nacre white. 
Observations. The regular ovate’ form of this shell will distin- 
guish it from most other species. ‘The young shell, however is broad- 
er behind, approaching to an oval figure, and is prettily ornamented 
with green rays on an olive yellow ground. 
Unio LIENOSUS. Pil. 1. ‘fig. 4. 
Shell narrow-elliptical ventticose 3 beaks approximate, little ele- 
vated and corrugated ; posterior biassl margin abruptly rounded ; pos- 
terior end sub-angulated ; cardinal teeth rather compressed and ob- 
lique, and double in both valves. 
- Tohabits small streams in South Alabama. Length 2.8 isin 
Cabinet of the Academy of Natural Sciences of Philadelphia. 
Shell narrow-elliptical, ventricose or inflated in old shells; sub- 
tance of the valves thick before and thinner behind; posterior dor- 
sal and basal margin rounded, and the end subangulated; beaks ap- 
proximate, not very prominent, and with interrupted undulations; 
concentric lines coarse and prominent ; epidermis very dark olive, 
and obscurely rayed ; wrinkled on the margin ; cardinal teeth double’ 
in both valves, a little compressed and oblique, and coarsely stria- 
ted; cavity most eapacious under the umbonial ae nacre vary~ 
ing Shain bluish white to deep salmon color, or purple. 
Observations. This species is remarkable for preferring the small- 
er streams to the rivers, and is not an uncommon shell in such waters, 
I found them in company with the U. rubiginosus, Lea, which though 
not very rare in the small creeks of South Alabama, I never found in 
either the Black Warrior or Alabama rivers. 
Unto STRAMINEUS. rica, fig. 6. 
Shell sub-oval, posterior side wider than the anterior and rounded ; 
beaks slightly prominent, with irregular undulations; umbones con- 
vex; concentric lines remarkably coarse arid prominent; cardinal 
teeth double in both valves, and sub-compressed : nacre pearly white 
and iridescent. 
Inhabits with the preceding species. Length 2.5 inches. Cabi- 
net of the Academy of Natural Sciences of Philadelphia. 
Shell sub-oval, convex, inflated behind the middle ; posterior side 
wide and rounded at the end ; posterior dorsal and basal margins ab- 
ruptly rounded ; umbonial slope disposed to be subangulated ; surface 
