576 UNIO 
Unio natalensis Lea, Pr. Ac. N. Sci. Phila., VIII, 1864, -p. 
1133. JLvAc) .N..Se1.. Phila.) V1) 1866, paso pl. xc he see: 
Obs., XI, 1867, p. 63, pl. xx, fig. 57-—Sowersy, Conch. Icon., 
x VI 1868, ple Exx fig: 362. 
Margaron (Unio) natalensis Lea, Syn., 1870, p. 32. 
Unio rectilinearis Sowerby, Conch. Icon., XVI, 1868, pl. Lxv, 
he. 232. 
Var. africanus Lea. 
Shell smaller than U/. caffer, thinner, less inflated, with del- 
icate, uneven, concentric sculpture, appearing almost smooth ; 
umbonal region sometimes corrugated or having irregular, 
zigzag bars: epidermis lurid greenish or greenish-brown ; na- 
cre bluish, somewhat iridescent. 
Length 45, height 22, diam. 14 mm. 
South Africa. 
Unio africanus Lea, Pr. Ac. N. Sei. Phila., VIII, 1856, p..94; 
jl: Ac. NsJSct Phila: TN 18573 p:, 200) pl. xv oes 
Obs., VI, 1857, p. 20, pl. xxvit, fig. 15.—ReeEveE, Conch. Icon., 
XVI, 1865, pl. xx, fig. 100. 
Margaron (Unio) africanus Lea, Syn., 1870, p. 48. 
Nodularia caffer var. africana SIMPSON, Syn., 1900, p. 825. 
Unio caffer Kuster, part, Conch. Cab. Unio, 1856, p. 143, pl. 
BSED s1uSi3 Ps 
Unio niloticus Kuster, Conch. Cab. Unio, 1856, p. 158, pl. xLv, 
fig 5. 
Var. vaalensis Chaper. 
Shell smaller than the type, rather thinner, more compressed ; 
beaks and umbonal region with zigzag sculpture, which 
changes with the later growth to granularly sulcate and finally 
plainly sulcate; epidermis dull, tawny greenish, or brownish. 
Length 40, height 18, diam. 11 mm. 
Vaal River, South Africa. 
Unio vaalensis CHarer, Bull. Soc. Zool. Fr., X, 1885, p. 480, 
ply xi, fies. 153: 
Nodularia caffer var. vaalensis SIMPSON, Syn., 1900, p. 825. 
