t^^l

VSIO: XODULAETA. 135
pseudocardinals compressed; beak cavities well excavated, not
compressed. Animal highly coloured, anal opening crenulate or
smooth."
265. Unio mongolicus, Middendorff.
Unio mongolicus, Middendorff, Sib. Eeise, ii, 1851, p. 277, pi. 27,
figs. 7, 8; Hesslinrr, Perl, und Ihre Perlen, 1859, p. 203;
Schrenck, Eeise und Forsch. im Amur-Lande, ii, 1867, p. 699:
Westerlund, Kong. Svensk. Vet.-Ak. Handl. xiv, no. 12,1876,
p. 74; P8etel,"Conch. Sam. iii, 1890, p. 159 ; Westerlund, Faun, der
Pal. ii, pt. 7, 1890, p. 113.
Original descrijttioti:—Testa transversim oblonga, subreniformi,
tumescente, fusca; latere postico antioum quater superante; margine
yentrali nonnihil retu.so,- margine cardinal! prime ventrali
parallel! et turn, inde a dimidio latitudinis, in rostrum asymmetricum,
inferum, descendente; umbonibus prominulis, erosis ; dentibus
cardinalibus parvis, ci'assiuaculis ; dentibus lateralibus
evolutis.
Long. 32, lat. 76, diam. 24 ram.
Uab. A mountain stream at Gorbitza in Daurien.
There is a single specimen in the IN^ational Collection which
is indistinguishable from that in the Indian Museum from the
Tipper, Indus.
Genus NODULARIA.
Nodularia, Conrad, Proo. Acad. Nat. Sci., Philadelphia, vi, 1853,
p. 268 ; Simpson, "Washington, D.C., Smiths. Inst., Nat. Mus.
Proc. xxii, 1900, p. 806.
TYPE, Unio doiiglasice, Gray; China.
Range. China; Japan; Eastern Siberia; Indo-China; India;
Borneo ; Java ; Sumatra; iSTew Guinea; Africa.
Shell nodose ; cardinal teeth robust, single in the right valve;
in each valve the principal cardinal tooth is parallel with the
lateral teeth, or directed towards the posterior extremity of the
shell.
See above.
Section NODULARIA {sensu slticto).
266. Nodularia (Nodularia) digitiformis (Soiverhy).
Nodularia [Nodularid) digitiformis (Sowerby) ; Simpson, Washington,
D.C., Smiths. Inst., Nat. Blus. Proc, xxii, 1900, p. 809.
Unio digitiformis, Sowerby, Oonch. Ion. xvi, 1868, pi. 66,
fig. 333 ; Pretp], Conch. Sim. iii, 1890. p. 150.