286 Records of the Indian Museum. [Vou. VII, 
Faun. Pal., II, Pt. 7, 1890, ‘p. 185 3 Loeard, Coquide Br aso0a: 
p- 149, fig. 162,—Unzio elongatus, Nilsson, Hist. Moll. Swec., 1822, 
p. 16; Sowerby, Conch. Icon., XVI, 1868, pl. Ixxvi, fig. 397,— 
Alasmodonta arcuata, Barnes, Am. Jl. Sci., VI, 1823, p. 227, pl. 
xii, fig. 20,—Mya arcuata, Eaton, Zool. Text book, 1826, p. 222, 
=Alasmodon arcuata, Stimpson, Shells of New Eng., 1851, p. 15; 
Kuster, Conch. ‘Cab:, 1856, =p. 2035. pl. xxxix#Gne 1 —— Woz 
sinuata, C. Pfeiffer, Nat. Deutsch L. & W.°Moll., Pt. 2, 1825, 
p- 33, pl. vi, fig. 4,=Unzo rotssyi, Michaud, Comp. Hist. Moll. 
Fr., 1831, p. 112, pl. xvi, fig. 28,—Margaritana roissyi, Wester- 
lund, Faun. Pal., II, Pt. 7, 1890, p. 186,—Unio tristis, Morelet, 
Moll. Portugal, 1845, p. 107, pl. xiii, fig. 2,—Margarita (Unio) 
crassiamus, Lea, Syn., 1836, p. 40; 1838, p. 26,—Unio (Alasmo- 
donta) dahuricus, Middendorff, Bull. Phys. Math. Ac. St. Petersb.., 
EX, £650; prt Sib Reise Il n85 1p: 275, plas ineemonnee 
=Unio dahuricus, Middendorff, L. & S. Moll. Sib., 1859, p. 26,= 
Unio (Margaritana) dahurica, Kobelt, Abh. Senck. Nat. Ges., XI, 
1875, pi427;. Kobelt? Faun Jap: a xt..01870.9p2 143 spies 
figs. I, 2, Alasmodon falcata, Gould, Proc. Boston. Soc. Nat. 
Hist. 11,1850, p: 204 ;-Otia “Conch. 5* 18629187. Uas: Bx 
Exp. XII, 1852, p. 433, figs. 545, 545@, 5450,—U™mo falcatus, 
Sowerby, Conch. Icon., XVI, 1868, pl. Ixxv, fig. 390,eUnio 
(Alasmodonta) complanatus, Middendorff, Sib. Reise, II, 1851, 
Pt. I, p. 273, pl. xxvii, figs. 1—6,—Margaritana complanata, 
Westerlund, Fauna Pal., II, Pt. 7, 1890, p. 187,—Alasmodon 
yubaensts, Trask, Proc. Cal. Acad. Sci., I, 1855, p. 30,—Margan- 
tana raveneliana, Chenu, Man., 1859, II, p. 144, fig. 714. 
Chitose, Yezo, Japan (J. Anderson), Reg. No. +82. 
Gen. Unio, Retzius, 1788. 
18. Unio mussolianus, Kiister, Conch. Cab. Unio., 861, 
p. 244, pl. Ixxxii, fig. 1,—Unio bourguignatianus, Lea, Proc. Ac. 
Nat. Sci. Philad. VIL, 1863p. 189: Jl; Acs Nat. ocr Philad avis 
1806, p. 54, pl. xviii, fig. 51,—Margaron (Unio) bourguignatia- 
nus, Lea, Syn., 1870, p. 39,—Umnio rasus, Lea, Proc. Ac. Nat, Sci. 
Philad,, VI1, 1863, p., 189; Jl, Ac. Nat. Sa.) Philady VE aceo: 
p. 50, pl. xvii, fig. 47,—Margaron (Unio) rasus, Lea, Syn., 1870, 
p. 58,—Umio mosulensis, Lea, Proc. Ac. Nat. Sci. Philad., VII, 
1863, p. 190; Ji Ac. Nat: Sci., Philad=, Vi, 1866 ep 152,plee<wae 
fig. 49,—=Margaron (Unio) mosulensis, Tea, Syn., 1870, p. 48,—= 
Margaritana mosulensis, Paetel, Conch. Sam., III, 1890, p. 173. 
River Tigris, Reg. No. 5941. 
19. Unio modiola,sp.n. (Pl. viii, figs. 1, 2.) 
Shell elongately oblong, somewhat curved, solid, covered with 
a chocolate coloured, laminiferous periostracum, both valves con- 
centrically striate ; umbones large, but not prominent, somewhat 
coarsely corrugate ; dorsal margin slightly arched ; ventral margin 
curvedly excavated in the median posterior region; anterior side 
somewhat produced, rounded above, sloping below; posterior 
