Myrtea. MOLLUSCA. VENERID^. 443 



EXTIXCT SPECIES. 



1. L. diva/ricatula. — Orbicular, gibbose, marked with two sets of oblique 

 arched striae, and three or four deep lines of growth — Sower. Min. Conch. 



t. ccccxvii. Lontion Clay. — Lamark and Sowerby agree in considering it as 



identical with the recent L. divarkata of the West Indies ! 



2. L. mitis Orbicular, convex, ornamented with minute longitudinal 



strire, and numerous small regular concentric laminae ; lunette oval, very con- 

 cave ; cardinal teeth obscure, no lateral tooth- — Sower. Min. Conch, t. olvii. 

 — London Clay. 



3. L. antiquata Orbicular, convex, ornamented with concentric laminae ; 



surface irregular ; anterior side angular ; lunette flat, lanceolate.— iSower. 

 Min. Conch, t. Dlvii. f. 2. — In Crag. 



4. L. crassa Nearly orbicular, convex ; covered with thick slightly ele- 

 vated concentric laminae ; superior margin obtuse ; lunette linear ; concealed ; 

 valve thick. — Soioer. jNIin. Conch, t. nlvii. f. '6. —Oolite. 



Gen. CXXV. MYRTEA.—" Oval-triangular, equivalve, 

 nearly equilateral, closed ; hinge of one valve, with a single 

 tooth and lateral one each side ; of the otlier valve, two 

 teeth, the lateral ones obscure."" — Turton. 



509. M. spinifera. — Shell with about thirty-six regular, con- 

 centric, elevated, and somewhat reflected, ridges. 



Venus spin, Mont. Test. Brit. 577- t. xvii. f. i.— M. spin. Turt. Biv. 

 Brit. 133 Western coasts of England, rare. 



Length half an inch, breadth a little more ; yellowish-white ; the ridges 

 become confluent in pairs on the retral edge, forming short obtuse reflected 

 spines ; beaks small, nearly central, inclining, below which is a lanceolate de- 

 pression. 



VENEKID.^. 



Gen. CXXVI. CYPRINA. — Shell subcordiform, nearly 

 eqviilateral, closed, hinge with three diverging teeth, and a 

 remote lateral one at the retral termination of the liga- 

 ment ; syphons not produced, leaving the marginal impres- 

 sion of the cloak entire, resembling, in this character, the 

 genus Astarte. 



510. C. islandica. — Obliquely heart-shaped, beaks prominent, 

 concentrically striated, and covered with a thick brown cuticle. 



Conclia e maximis. List. An. Ang. 173. Conch, t. cclxxii Venus isl- 



Linn. Syst. i. 1131. Mull. Zool. Dan, t. xxviii. f. 1-5. Mont. Test. 



