UNIO 575 
only moderately full; posterior ridge full, angled or narrowly 
rounded, sometimes partly double, ending below the median 
line; anterior end rounded: base line straight, incurved in old 
shells, usually full near the posterior end; dorsal line curved ; 
dorsal slope curved or obliquely subtruncate; surface irregu- 
larly concentrically sculptured, the sculpture being sometimes 
broken, subnodulous or slightly zigzagged; epidermis dirty 
greenish-yellow or brown; hinge moderately solid; pseudocar- 
dinals rugose; laterals somewhat remote; muscle scars well 
impressed ; nacre dirty or lurid, yellowish or lead-colored. 
Length 67, height 34, diam. 25 mm. 
Length 73, height 39, diam. 28 mm. 
South Africa. 
Unio caffer Krauss, Sud Af. Moll., 1848, p. 18, pl. 1, fig. 14. 
Kuster, part, Conch. Cab. Unio, 1856; p: 143, pl. x11, 
fig. 2—Hantey, Biv. Shells, 1856, p. 385, pl. xx1, fig. 40.— 
Sowersy, Conch. Icon., XVI, 1866, pl. x11, fig. 226. 
Margaron (Unio) caffer LEA, Syn., 1852, p. 32: 1870, p. 48. 
Nodularia caffer S1MPSON, Syn., 1900, p. 825. 
Cafferia caffra Connotiy, Ann, S. A. Mus., XI, 1912, p. 271. 
Unio seyheri MEN KE, Zeitschr. Mal., 1848, V, p. 28. 
Unio cyamus Priiiprr, Zeitschr. Mal., V, TSE Taps 125. 
Unio verreauianus Lea, Pr. Ac. N. Sci. Phila., VIII, 1856, p. 
SA A@bs W 1os7-9: 20, pl. xxvii, fig: 167 Jl. Ac. N. Sci. 
pital tess. p. 201, pl. XVII, Hg. 16: 
Unio verrauianus Sowrrsy, Conch. Icon., XVI, 1868, pl. Lx1x, 
fig. 352. 
Margaron (Unio) verreaurxianus Lea, Syn., 1870, p. 36. 
Unio verreauxt Pater. Conch. Sam., III, 1890, p. 171. 
Unio navigoliformis Lea, Pr. Ac. N. Sci. Phila., XI, 1859, p. 
152; Ji. Ac. N.-Sci. Phila.; IV,. 1860, p. 248, pl. xxxvut, fig. 
124; Obs., VII; 1860, p. 63, pl. xxxvu, fig. 124.—REEVE, 
Conch. Icon., XVI, 1865, pl. xx1v, fig. 114. 
Margaron (Unio) navigoliformis Lea, Syn., 1870, p. 31. 
