UNIO 649 
pseudocardinals and two laterals, the upper smaller ; right valve 
with one pseudocardinal and one lateral; muscle scars well 
marked ; nacre pale brownish-purple, rather dull. 
Length 77, height 32, diam. 21 mm. 
Southern Georgia. 
Type locality, Satilla River, Camden Co., Ga. 
Unio hazelhurstianus Vea, Pr. Ac. N. Sci. Phila., II, 1858, p. 
roost. Ac Ne Sei. Piila.,1V, 1850,/p: 201, pl. x xvi, fig. 92; 
Obs.,. VII, 1859, p. 29, pl. xxvt, fig. 92,—Sowerby, Conch. 
Icon., XVI, 1866, pl. xxxv, fig. 188-—Simpson, Syn., 1900, 
Pp. 719. 
Margaron (Unio) hazelhurstianus Lea, Syn., 1870, p. 60. 
The surface is sculptured with rather fine, concentric ridges, 
the epidermis is black and thick and unless rubbed is dull. Dr. 
Lea has placed with his hazelhurstianus two shells, which | 
am sure are naviculoides, that being a thinner, more rhomboid 
form with smoother, lighter colored epidermis. 
Unio PyGAMA&uS Lea. 
“Shell smooth, elliptical, rather compressed, striate, rounded 
before and angular behind: substance of the shell rather thin, 
thicker before ; beaks somewhat prominent ; ligament short and 
thin; epidermis dark brown, striate, with obscure rays, and 
slightly polished ; umbonal slope angular; marks of growth in- 
distinct ; cardinal teeth small, compressed; lateral teeth rather 
long, linear, slightly curved and thickened at the posterior end ; 
anterior cicatrices distinct ; posterior cicatrices confluent: dor- 
sal cicatrices in the centre of the cavity of the beaks; cavity 
of the shell shallow; cavity of the beaks small and angular ; 
nacre blue and very iridescent behind. 
Mength r2cheicht..7, diam. 4 inches?’ (Lea:) 
Type locality, Abbeville District, S. C. 
Unio pvemeus Les, Pr. Am. Phil Soc., V, 1852, p. 2: ; 
Am. Phil. Soc., X, 1852, p. 262, pl. xv, fig. 14; Obs., V, 1852, 
pl. 18, pl. xv, fig. 14——Stmpson, Syn., 1900, p. 715. 
Margaron (Unio) pygmeus Lea, Syn., 1870, p. 48. 
