TRIBE SOLENID^. 11 



the margin : anterior side quadruple the length of the posterior, 

 and rounded at tlie extremity : gape very large. J^. . U. — lale of 

 Plata. 



G. Brevis. Sow, Z. P. 1834. Abbreviated-ovate, thin, pel- 

 lucid, striated : anterior side seven times as long as the posterior. 

 ^ . . 1^. — Gallapagos. 



G. Hyalina. Sow. Z. P. 1834. Oval, whitish, hyaline, 

 smoothish, with the back longitudinally striated : posterior side 

 short; gape equal to fds of the length of the shell, ^o^^- — ■^o?yZ 

 Hood's Inland. 



G. RuGOLOSA. Sow.Z.P. 1834. Oblong, whitish, striated, 

 rugulose ; the posterior wrinkles near the gaping margin, crowded 

 and acute ; gape extremely long. 2^4. — (rallapagos. 



TRIBE SOLENIDiE. 



Shell transversehj elongated, destitute of accessory pieces, and 

 gajjing at the lateral extremities only ; ligament external. 



SOLEN. 



Equivalve, transver.sely elongated, gaping at both extremities ; 

 beaks very small, prominent ; primary teeth small, varying in 

 nnmher, sometimes none, seldom inserted in a cardinal pit ; liga- 

 ment external. 



* Hinge terminal. 

 S. Vagina.* Lin, 1113 — D.p. 57. — Lam. 1. — Don. t. HO. 

 —Mont. p. 48.— Turt. B. p. 79.— W. t. 3./. 3. Sub-cylindrical, 

 becoming more compressed towards the truncated anterior extremity, 

 orange-yellow sometimes stained with brown : a stricture across the 

 posterior extremity which is slightly oblique : a single tooth in each 

 valve, the opposite sides strengthened by a rib. 1 ..5. — Europe. 



S. CoRNEUs. Lam. 2. — Del. t. 2,f. 2. Small, linear, straight, 

 margins nearly parallel, uniform horn-coloured, epidermis very 

 thin : hinge with a single tooth in each valve. 2. — Java. 



S. Vaginoides. Lam. 3. — Del, t. 2. f. 3. S. Corneus, 

 W.S.t. 1./. 2. Linear, slightly curved, reddish; hinge with 

 one tooth in each valve. 3|. — Isles of New Holland. 



S. SiLiQUA.* Lin. 1113.— Z>. p. 5S.~La?n.4.— Ch. /. 29.— 

 Don. t. 46.^Mont. p. 46.— Turt. B. p. SO.—W.t.'s.f. 1. 

 Straight, with an olive brown cuticle, which is darkest at the 

 posterior extremity: a single tooth and a remote lateral lamina in 

 one valve, m the other, two besides a lateral inclined tooth, coitcs- 

 ponding with the opposite lamina. 1 . . 7. — Europe. 



S.Ensis.* Lin. l\\4.— D. p. 59.— Lam. 5.— Ch.f. 29, 30.— 



