664 UNIO 
This species has more the form of a member of the buckleyi 
group than of that of the complanatus group, but it has the 
nacre and epidermis of the latter. It is duller colored than the 
average manifestation of the ftiomeyi combination, and is 
more nearly elliptical or ovate than that species. 
UNIo aguiuus Lea. 
Shell elongated, nearly evenly elliptical, compressed, rather 
thin to subsolid, inequilateral ; beaks low, subcompressed, their 
sculpture numerous strong ridges which are curved up behind, 
the sculpture extending well on to the disk; posterior ridge 
distinct though not high, subangular, scarcely double, ending 
behind in a point just below the median line; above this point 
there is a short, oblique subtruncation and on the dorsal slope 
there are two or three faint radiating ridges ; growth lines un- 
even; epidermis dirty greenish or greenish-brown, scarcely 
rayed, dull; pseudocardinals rough, subcompressed; laterals. 
nearly straight, two in the right valve and a somewhat double 
one in the left; muscle scars shallow; nacre bluish-white to. 
purplish, rather bright. 
Length 65, height 30, diam. 16 mm. 
South Georgia and northern Florida. 
Type locality, Flint River, Macon and Chattahoochee River, 
Roswell, Ga. 
Unio aquilus Lea, Pr,.Ac..N, Sei. Phila, [X, 98575 p. 17230 
AcoN, Sct. Phila; V,18sS, ps 02, ple ome 72) Ops anal 
1858, p. 92, pl. xx, fig. 72.—Simpson, Syn., 1900, p. 727. 
Margaron (Unio) aquilus Lea, Syn., 1870, p. 60. 
The disk is often ornamented by a number of faint, almost 
vertical, corrugations, which sometimes become subnodulous. 
It is smaller, more compressed, thinner and duller colored than 
U. ocmulgeensis. There are sometimes a few dark rays on the 
dorsal slope. 
UNIO ICTERINUS Conrad. 
Shell oblong, subelliptical or subrhomboid, convex, solid, in- 
equilateral; beaks moderately full and elevated, their sculpture 
a number of strong concentric ridges; posterior ridge prom- 
