TRIBE NYMPHACEA. 83 
6.f. 14. Trapeziform, transverse, turgid, sub-equilateral, longitu- 
dinally grooved, white reticulated with reddish brown spots, posterior 
end nearly smooth, anterior slope gibbous in the middle: pale 
orange rufous within, the margin serrated. 1.—New Holland.— 
Scarcely a Donasx, the hinge more resembling that of Cardium 
Medium, and the palleal scar not sloped posteriorly. 
D. Merorz. Lam. 22.—Venus. M. Lin. 1132.—D. p. 185. 
—W.t. 8. f. 62.—Ch. f. 450, 1, 2.—H. t. 261. f. 1.—List. t. 
378. f. 221. Ovate, triangular, compressed, with narrow transverse 
parallel grooves, variable in colouring, but generally whitish, tinged 
more or less with fulvous, and covered with abroad zig-zag stripe of 
a purplish or liver colour: anterior slope excavated.—Variety.— 
Uniform white or purple. (Ch. f. 453). 2.—India. 
D. Scrrera.* Lin. 1127.—D. p. 154.—Lam. 23.—List. t. 
379. f. 222.—H. t. 261.f. 2, 3, 4.—Ch. f. 261, 2, 3.— W. t. 6. 
15. Ovate, somewhat flattened, smooth, white with waved lines and 
spots (which are usually parallel) of a purplish orange reddish or 
fawn colour ; anterior depression hollowed and the ligament sunk in 
a groove: margins acute.—Jndia.* 
D. Anatinum.* Lam.—Blain. t. 72. f. 2.—D. Truncuuus. 
W.t. 6. f. 5. (not Lam. 24.)\—Don, t. 29. f. 1.--D. p. 150.— 
Lis. t. 376. f. 217.—Dors. Cat. t. 6. f. 3.—Da Costa. t.14 f. 
3. Oblong wedge-shaped, with the hinge margin nearly straight ; 
glossy, with numerous minute longitudinal simple striz, becoming 
obsolete towards the anterior end, which is shorter, smooth, and 
very obliquely truncated ; yellowish olive, with two or three pale 
rays, and darker or lighter bands ; violet within : a single lateral 
tooth. #..13.—Hurope$s 
D. Faspacetia. Lam. 25. Transversely oblong, with the an- 
terior side short oblique convex and sub-carinated ; whitish some- 
what tinged with red, and indistinctly rayed: the transverse striz 
decussated by extremely fine longitudinal ones. 1.6 

4 Both this and the preceding species are more allied to Cytherea 
than Donax. There are three cardinal teeth in the right and two 
in the left valve, the posterior tooth confounding itself with the 
nymph. These cardinal teeth are disposed differently from those 
of Donax proper. 
° We have given a copy of the D. Srriatus of Chemnitz (W. t. 6. 
J. 7.) which 1s probably an exaggerated figure of this species ; cer- 
tainly it is not the Striatus of Linné. 
6 This is probably the same as D. Semisrrrata. Poli. t. 19. f. 
7.—Philip. p. 36. t. 3. f. 12. Oblong, wedge-shaped, usually 
drab with two white rays, very smooth posteriorly, anteriorly with 
decussating striz : anterior slope with strong transverse grooves, its 
G2 
