Myrtea. 
MOLLUSCA. VENERIDiE. 
443 
EXTINCT SPECIES. 
1. L. divaricatula. — Orbicular, gibbose, marked with two sets of oblique 
arched striae, and three or four deep lines of growth.— *<S'ozcer. Min. Conch, 
t. ccccxvii. — London Clay. — Lamark and Sowerby agree in^ considering it as 
identical with the recent L. divaricata of the West Indies ! 
2. L. Orbicular, convex, ornamented with minute longitudinal 
striae, and numerous small regular concentric laminae ; lunette oval, very con- 
cave ; cardinal teeth obscure, no lateral tooth* — Sower, Min. Conch, t. nlvii. 
— London Clay. 
3. L. ant'iquata. — Orbicular, convex, ornamented with concentric laminae ; 
surface irregular ; anterior side angular ; lunette flat, lanceolate. — Sower. 
Min. Conch, t. nlvii. 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. — Sower. Min. Conch, t. nlvii. f. ^.—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 other valve, two 
teeth, the lateral ones obscure.” — Turton. 
509. M. spinyira . — 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. 
VENEHIDiE. 
Gen. CXXVI. CYPRINA. — Shell subcordiform, nearly 
equilateral, 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, resembhng, in this character, the 
genus Asta?'te. 
510. C. islandica. — Obliquely heart-shaped, beaks prominent, 
concentrically striated, and covered with a thick brown cuticle. 
Concha 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. 
