t^^l

3S-0BULA.UIA. 141
tooth also on the margin, at the base of which appears a second
and much smaller tooth; posterior lateral gently curved, narrow,
sharp, falling between two equal sized lamella) in the left valve;
anterior muscular scar moderately to slightly deep, posterior
muscular scar superficial.
Long. 27, lat. 47-25 mm.
Hob. Eivers of India; Pegu (Ind. Mus. Coll.).
The species seems to vary greatly in shape and colour, some
specimens, in the long series of the Indian Museum Collection,
being posteriorly much more rostrate than others, while in some
the dorsal margin is angled posteriorly and produced anteriorl}'.
In colour the species seems to vary from pale yellowish green to
dark blackish brown, and thus two extremes might easily be
taken at first sight for different species : there does not seem,
however, to be any clear line of demarcation between the many
varieties, all of which merge into one another when a sufficiently
large series is examined.
273. Nodularia (Nodularia) pugio {Benson).
Nodidaria {Nodularia) ptigio (Benson); Simpson, Washington, D.C,
Smiths. Inst., Nat. Mus. Proc. xxii, 1900, p. 814.
XJnio pugio, Benson, A. M. N. H. x, 1862, p. 193; Sowerby, Conch.
Icon. pi. 45, fig. 516; H. & T., C. 1.1876, p. 5, pi. 10, iig. 7.
Original description:—-Testa transverse elongato-triangulari,
linguseformi, valde iniequilaterali, compressiuscula, crassa, antice
brevissima, subito descendente rotundata, postice sensim angustiore,
cuneiformi, demum acuminata, margine dorsali recta,
ventrali convexiusculo, postice ascendente; umbonibus late
plauatis, lajvibus, prominentibus, carina umbonali subito obtuse
angulata, area interjacente versus cardinem descendente; disco
gubplanulato, laeviusculo, substriato; dente cardinali (valvie
dextr8e)brevi, crassa prominente, radiato-sulcata, lateral! elongata,
subduplicata, iutns creriulata: margarita albida, iridescente.
Long. 21, lat. 42, diam. 16 mm.
Hob. Neighbourhood of Ava, Pegu (Indian Mus. Coll.) ; also
recorded from the Barrack Eiver, Silchar.
A curious species whose smooth surface and anteriorly swollen
and posteriorly cuneiform shape easily distinguish it from any
other Indian members of the family.
274. Nodularia (Nodularia) grattosa {PhiU]}]^).
Nodularia {Nodularia) grutiosa (Philippi); Simpson, Washington,
D.C, Smiths. Inst., Nat Mus. Proc. xxii, 1900, p. 815.
C/n/o (/ra^j'osMs, Philippi, Conch, i, 1845, p. 20, pi. l,fig. 5; Catlow
& Reeve, Conch. Nom. 1845, p. 59; ? Kiister, Conch. Cab., Unio,
1861, p. 239, pi. 80, fig. 3.
Margaron {Unio) gratiosus, Lea, Syn. 1870, p. 32.