346 CRETACEOUS MOLLUSCA, 
Descriptions of the Shells of the Chalk Formation. 
By JAMES DE CarLe Sowersy, Esq. 
MOLLUSCA. 
BRACHIOPODA. 
Terebratula sexradiata. (Tab. XXVII. fig. 10.) 
Spec. Cuar.—Lenticular subpentagonal, minutely granulated ; central area 
flattened with three obscure rays on each side; beak very short with a large 
aperture. 
Somewhat resembling Magas pumila in form, but the valves are both convex ; 
the rays, which form its strongest character, are slightly elevated. 
Terebratula Bulla. (Tab. XXVII. fig. 11.) 
Spec. Cuar.—Short oval, inflated, smooth ; beak incurved, with a round aper- 
ture in the adpressed apex ; front broad, elevated. 
More elongated and larger than Terebratula subglobosa. 
Terebratule. (Tab. XXVII. figs. 15, 16, 17.) 
In the present unsettled state of the genus Terebratula, I will not venture to 
name these shells from the single specimens which alone have come into my 
hands. 
CONCHIFERA DIMYARIA. 
Teredo rotundus. (Tab, XXVIII. figs. 27 & 28.) 
Sprc. Cuar.—Nearly globose, finely striated; anterior extremity nearly 
closed, posterior extremity short. 
A small shell from the chalk of Kent. 
Mus. Sowerby. 
Leda pulchra. (Tab. XXVIII. fig. 10.) 
Spec, Cuar.—Ovate ventricose, concentrically striated ; posterior lobe small, 
pointed, beak-shaped. 
Found in the chalk of Kent. 
