TRIBE SOLENID.'E. 1 1 



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

 and rounded at (he extremity : gape very large. T T () . . I 1 . — Isle of 

 Plata. 



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

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

 \ . . -i. — 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. 6 o^ 1 - — Lord 

 Hood's Island. 



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 . — Gallapagos. 



TRIBE SOLENIDtE. 



Shell transversely elongated, destitute of accessory pieces, and 

 gaping at the lateral extremities only ; ligament external. 



SOLEN. 



Equivalve, transversely elongated, gaping at both extremities ; 

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

 number, sometimes none, seldom inserted in a cardinal pit ; lirja- 

 ment external. 



* Hinge terminal. 



S. Vagina.* Lin. 1113 — D.p. 57. — Lam. 1. — Don. t. 110. 

 —Mont. p. 4S.—Turt. B. p. 79.— W. t. 3.f. 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./. 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. l.f.2. Linear, slightly curved, reddish; hinge with 

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



S. Siliqua.* Lin. 1113.— D.p. 58.— Lam. 4.— Ch. f. 29 — 

 Don. t. 4.6.—3Iont. p. 46.—Turt. B. p. 80.— W. t.'3. 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, in the other, two besides a lateral inclined tooth, corres- 

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



S. Ensis.* Lin. 1 1 14. — D. p. 59.— Lam. 5.— Ch.f. 29, 30.— 



