UNIO 631 
with a faint upper one in the right valve; laterals curved: 
muscle scars small: nacre dirty copper-colored, irridescent be- 
hind. 
Tength 42, height 23, diam. 14 mm. 
Type locality, Orange Springs, Marion County, Florida. 
Umno subluridus Stmeson, Pr. U. S. Nat. Mus., XV, 1892, p. 
AZ2 Dio LXXUL, HES. 34> Synth, TODO; p.-743. 
! can not be certain as to the relationship of this species, as 
the beaks are eroded in the only shells I have seen. I placed 
it in the section Uniomerus in the Synopsis, but am rather in- 
clined now to put it near Unio coruscus and buckleyi. One of 
the three specimens I have before me is distinctly biangulate 
behind. The anterior end is rounded in front, not truncate as 
it is in coruscus. 
Unto coruscus Gould. 
Shell generally oval, sometimes subrhomboid, subinflated 
to intlated, subsolid to solid, inequilateral ; beaks moderately 
full, somewhat elevated, their sculpture not observed; poste- 
rior ridge full, rounded, sometimes imperfectly double below 
and ending in a blunt point or slight biangulation at or below 
the median line; anterior end usually more or less truncated, 
ending in an angle above; dorsal and basal lines curved; sur- 
face commonly smooth: epidermis tawny, yellowish-green to 
reddish-brown, sometimes clouded or faintly rayed, shining ; 
left valve with two compressed to stumpy, ragged pseudo- 
cardinals and two curved laterals ; right valve with’one pseudo- 
cardinal, often with a second small one above it and one lat- 
eral ; beak cavities shallow; muscle scars deep in heavy shells, 
shallow in thin ones; nacre purplish, dull or slightly shining, 
sometimes iridescent behind. JI,ength of a shell in the Lea col- 
lection presented by Dr. Gould, 29, height 17.5, diam. 31 mm. 
Length 48, height 24, diam. 17 mm. 
Length 7o, height 40, diam. 30 mm. 
Florida. 
Type locality, River St. John’s, near Lake Beresford, Fla. 
