690 UNIO 
dinal ridges; posterior ridge full, subangular, inclined to be 
double below, ending in a slight biangulation behind at and 
below the median line; base a little produced behind the mid- 
dle; surface finely, concentrically sulcate; epidermis bright 
yellowish-green, with one or two faint rays on the dorsal 
slope, polished ; pseudocardinals subcompressed, double in the 
left valve and single in the right; laterals long and delicate; 
muscle scars shallow: nacre bluish. 
Length 35, height 14, diam. 8 mm. 
Type locality, Neuse River, near Raleigh, North Carolina. 
Unio viridulus Les, Pr. Aco N: Sci. Phila, VIL; 1863, ps 103; 
jJiAcNat.-Sct. Phila. Vi, 1866, p.-1o;spls im, sescr7 Oese 
XI, 1867, p. 14, pl. 1, fig. 17—SIMPson, Syn., 1900, p. 734. 
Margaron (Unio) viridulus Lea, Syn., 1870, p. 58. 
Evidently a young shell and it may be the young of some 
other elongated species, which has a dark epidermis when 
adult. I do not think it is a young lanceolatus, as it is fuller 
on the posterior half of the base line than that species and has 
a somewhat double, broader posterior ending. Besides, it is 
more decidedly concentrically suleate than anything I know 
of that species. 
Unto propuc’ttus Conrad. 
Shell elongated, subcompressed or compressed, subsolid, in- 
equilateral, the dorsal and ventral lines nearly straight and 
parallel, the anterior end rounded, but often cut away a little 
below ; posterior end drawn out to a point at or a little below 
the median line; posterior ridge rather low ; beaks not elevated 
or full, their sculpture not seen: surface having fine, uneven, 
incremental sculpture; epidermis dark reddish-brown or green- 
ish-brown, subshining; pseudocardinals small, stumpy, two in 
the left valve and one in the right; left valve with two remote 
laterals ; right valve with one, which is often somewhat double ; 
anterior scars impressed; posterior scars shallow; nacre pur- 
plish, often salmon-tinted. 
Length 67, height 26, diam. 15 mm. 
Length 68, height 24, diam. 14 mm. 
