UNIO 635 
I have only seen the type of this. It is rather short, solid, 
inflated, with a high, sharp posterior ridge. ‘The epidermis is 
bright, rich brown, and on the posterior slope there are traces 
of two faint radial ridges. The pseudocardinals are rather 
compressed for so solid a shell; the nacre is very rich and 
brilliant. In some respects it seems close to U. buckleyi, but 
the high sharp posterior ridge and subrhomboid form ally it 
to the crassidens group. 
Unio CUNNINGHAMI B. H. Wright. 
Shell usually subrhomboid, sometimes decidedly rhomboid, 
solid, subinflated to inflated, inequilateral; beaks apparently 
full and somewhat elevated, but too much eroded in all the 
examples seen to show any characters; posterior ridge de- 
cidedly developed, narrowly rounded, ending in a rather sharp 
point at or near the base; ventral outline generally straight, oc- 
casionally a little incurved; anterior end rounded or truncate, 
usually angled above; dorsal slope obliquely truncated ; surface 
with irregular growth lines; epidermis shining greenish-yel- 
low, tawny, ashy-brown or brown, sometimes clouded or faint- 
ly rayed with green; pseudocardinals compressed to solid, rag- 
ged; laterals short and curved; muscle scars small and im- 
pressed: nacre silvery, purplish, salmon or reddish, often 
bright. 
Length 52, height 39, diam. 23 mm. 
Length 46, height 26, diam. 24 mm. 
Florida. 
Type locality, Lakes of Sumpter Co., Fla. 
Unio cunningham: B. H. Wricut, Pr. Ac. N. Sci. Phila., XIII, 
1883, p. 58. pl. 1, figs. I-4——Sr1mpson, Pr. U. S. Nat. Mus., 
XV, 1892, p. 422, pl. Lxv, fig. 6;—Syn., 1900, p. 714. - 
Closely related to U. micans and U. coruscus. It is solider 
and more inflated than the former, is generally lighter colored 
than the latter, and is more decidedly rhomboid and has a 
higher posterior ridge than either. 
