9D 
* Ribs spinous or tuberculated. 
C. AcuLEatum. Lin. 1122—D. p. 115—Lam. 14— 
EB. M. t. 297. f. 5—Ch. f. 157—Pen. 4. p. 187. ¢. 
53. f. 1.-—Don. t. 6—Mont. p. 77—Lin. T. 8. p. 62— 
Wood. G. C. p. 207. €. 51. f. 1—Turt. C. D, p. 28— 
Turt. B.p. 181. t. 13. f| 6, T—F. p. 420—(Young, 
C. Sprnosum. Sow. Brit. Mis. t. 32)—Very tumid, 
comparatively light, oblique, subangulated anteriorly ; 
with about twenty-one ribs armed anteriorly with long 
sharp spines (Jancet-shaped but round in the old shells) 
posteriorly with rather flattened obtuse tubercle, trans- 
verse striz only in the interstices of theribs. 4. W. 
Coasts. 7 
C. TuBercuratum. Lin. 1122—D. p. 117—Lam. 
15—Pen. 4. p. 88—Don. t. 107. f. 10—Mont. p. 568. 
—Ian. T.8.p. 64—Wood. G. C. p. 210. t. 50. f. 1, 2 
—Dor, Cat. p. 31. t.2. f. 2.—Turt. D. p. 28. f. 
12.—Turt. B. p. 183.—F. p. 421.—Subglobular, 
ponderous, a little truncated anteriorly, with twenty- 
one tibs armed anteriorly with tubercles, posteriorly 
with scaly plates; pale chesnut usually with darker 
zones, the transverse wrinkles crossing the ribs. 4. 
W. Coasts. 
