t^^l

170 UNIONIDJE.
subventricose, couceutrically zoned with bluish green and ochraceous
yellow, rather glossy, smooth, except at the umbones, which
are adorned with longitudinally divergent slender corrugations,
the hinder lines of which incline interiorwards, the front ones
posteriorwards ; a few similar wrinkles radiate subtransversely
thence to the dorsal end of the concave anterior slope; ventral
edge convex; front dorsal edge straightish, a little elevated ;
extremities rounded, the front rather broad ; nacre silvery ;
umbonal cavity ample ; teeth laminar, compressed.
Long. 19, lat. 26-5 mm.
Hah. Assam.
The species was originally described from a single ^ alve: below
are given the dimensions of two specimens in the British and
Indian Museums collections respectively :-—
Lat
1.
.... 16-75
.. . . 25-5
. . . . 13
2.
19 mm.
30 mm.
14-75 mm.
The above two specimens are the only ones which the compiler
of the present volume has been able to examine: though agreeing
in the essential characters with the original description, there are
still considerable difi'erences between, them : the smaller, or British
Museum specimen, being far more obtuse posteriorly than that of
the Indian Museum, the dorsal margin of the former gradually
sloping upwards posteriorly to a rounded angle, while in the latter
this character is not nearly so accentuated.
304. Parreysia (Parreysia) burmaims (Blanford).
Parreysia (Parreysia') 4«)-HI««»/6'(Blanford); Simpsou, Washington,
B.C., Smiths, inst., Nat. Mus. Proc. xxii, 1900, p. 845.
Unio burmaims, Blanford, P. Z. S. 1809, pp. 449-450.
Unio hirinanus, 11. &• T., C. 1. 187C, p. 19, pi. 42, fig. 1; Psetel,
Conch. Sam. iii, 1890, p. 146.
Original description:—^Testa subovata, solida, subcompressa,
valde insBquilateralis, picea vel fusco-olivacea, concentrice plicatostriata,
disco medio et postico rugis obliquis irregulariter angulatis,
interdum granosis, hie illic prsBsertim versus marginem ventralem
obsoletis corrugato; umbonibus non prominentibus, subplanulatis,
angulatim corrugatis, baud procul ab extremitate anteriore positis;
lunella parva, concava; latere antico brevissimo subacuminatorotundato;
area convexa; margine dorsali poslice regulariter
convexo-curvato, terminaliter rotundato, ventrali convexo; deutibus
cardinalibus crassis, radiatim corrugatis, in valva dextra binis,
anteriore minimo, in sinistra ternis vel subternis; lateralibus
elongatis subcurvatis, in valva dextra subduplicibus, in sinistra
duplieibus ; margarita colore salmonis tineta. Testa junior