TRIBE NYMPHACEA. 55 



with concentric ridges, the interstices transversely striated, and in 

 parts sub-decussated. 1 ^. 



V. DiSTANS. Lam. 5. Rhombic ovate, white, spotted with 

 fulvous, finely striated longitudinally, a few distant tranverse ridges. 

 — South Seas, Island of St. Peter and St. Francis. — This and the 

 preceding closely resemble V. Irus. 



V. Crenata. Lam. 6. — Del. t. 5. f. 2. Ovate, anteriorly 

 rounded, fulvous white, with longitudinal and distant transverse 

 grooves, which towards the margin are crenated and ridge -like; 

 violet within. If.—Neiv Hollami. 



V. Carditordes. Lam. 7 . — Del. t. 5. f. 3. Ovate-oblong 

 and obtuse at the extremities, anteriorly narrower, whitish ; girt 

 with transverse ridges, the interstices longitudinally ribbed : within 

 quite white. 1^. — Nero Holland. Much resembling the last. 



V. Lajonkairii. Pay. t. 10. J". 11, 12. — Desh. in Lam. 6. 

 p. 164. Orbicular, sub -equilateral, gibbous, transversely grooved 

 and longitudinally striated ; beaks tumid, hooked and close : 

 posterior depression somewhat heart-shaped. — Corsica and Sicily. 



V. Monstrosa. Gray. An7i. Phil. 25. — Venus M. Gmel. 

 3280.— Z>. p. 208.— CA./. 445, 6.— TF. t. S.f. 112. Oval, one 

 valve larger than the other, dirty white internally, spotted with 

 purple, decussated by the striae, rounded at both ends, but broader 

 posteriorly. f..l^. — Nicohar Isles. 



TRIBE NYMPHACEA. 



Never having more than two primary teeth in the same valve ; 

 often gaping at the lateral extremities: ligament external; 

 nymphce tisually projecting outward. 



Section. — N. Solenaria. 



SANGUINOLARIA. 



Transverse, somewhat oval, slightly gaping at the lateral extre- 

 mities ; ventral margin arched, and not parallel to the dorsal 

 one; hinge with two approximate teeth in each valve. 



S. OcciDENS. Lam. 1. — Solen Occidens. Lin. 3228. — 

 n. p. 68.—^. t. 226./. 2.—Ch.f. 61.— TF. t. 3./. 29. Nearly 

 elliptic, one end rounded, the other very slightly truncated, rather 



^ We have figured the shell usually considered as this species, 

 ot vouching however for its identity. 



