UNIO 563 
pseudocardinal, often with a vestigial one above it and one 
lateral ; beak cavities not deep; nacre whitish, often somewhat 
silvery, a little thickened in front. 
Length 63, height 35, diam. 21 mm. 
Length 55, height 28, diam. 19 mm. 
Length 51, height 31, diam. 19 mm. 
Algiers ; Tunis; Asia Minor; Assyria; Southeastern Europe. 
Unio duriewi Desuayes, Hist. Nat. Moll. Alg. Atlas, 1847, pl. 
cIx, figs. 5-8.—Bourcuicnat, Moll. Alg., II, 1864, p. 288, pl. 
xIx, figs. 4-8.—SIMPSON, Syn., 1900, p. 694. 
Margaron (Umo) durieui L&a, Syn., 1852, p. 39; 1870, p. 48. 
Unio sitifensis Morevet, Jl. de Conch., II, 1851, p. 360. 
Unio orientalis Pourcuicnat, Test. Noviss., 1852, p. 209. 
Unio brugwierianus BouRcuIGNAT, Cat. Rais., 1853, p. 78, pl. | 
ul, figs. 54-58.—Kopbe rt, Icon., new ed., XIX, 1912, p. 39, 
plpx yx, tie 127 37. 
Margaron (Unio) brugmerianus Lea, Syn., 1870, p. 44. 
Unio vescoi Bourcuicnat, Rev. et. Mag., VIII, 1856, p. 74, 
pl. 11, figs. 4-8—Kopsett, Icon., [V, 1876, p. 66, pl. cxrx, fig. 
1154.° 
ne (Unio) vescot Lea, Syn., 1870, p. 46. 
Unio schwerzenbacht Bourcuicnat, Rev. et Mag., VIII, 1856, 
p- 75, pl. vin, figs. 1-5.—Kuster, Conch. Cab. Unio, 1862, 
p. 266, pl. xc, fig. 2—Sowrrsy, Conch. Icon., XVI, 1868, 
pl. xiv, fig. 241.—Kosevt, Icon., VII, 1880, p. 81, pl. ccv1, 
fig. 2099. 
Unio prusi Bourcuicnat, Rev. et Mag., VIII, 1856, p. 76, pl. 
11, figs. I-4. 
Unio damascensis Lua, Pr. Acad. Nat. Sci. Phila., VII, 1863, 
p. 190; Jl. Acad. Nat. Sci. Phila., VI, 1866, p. 55, pl. xvi11, 
fig. 52; Obs. XI, 1869, p. 59, pl. xvi, fig. 52.—KoseE-r, 
Icon., new ed., XVIII, 1912, p. 45, pl. p11, fig. 2656. 
Margaron (Unio) damascensis Lea, Syn., 1870, p. 52. 
Unio orontesensis Les, Pr. Acad. Nat. Sci. Phila., VII, 1863, 
p. 190; Jl.-Acad: Nat. Sci. Phila, VI, 1866, p. 53, pl. xvu1, 
fig. 50; Obs. XI, p. 57, pl. xvi, fig. 50.—Koser‘, Icon., 
new ed., XVIII, 1912, p. 45, pl. piu, fig. 2650. 
Margaron (Unio) orontesensis Lea, Syn., 1870, p. 52. 
