17 



tudinal furrow, smooth, white, frequently deeply- 

 grooved at the base, posterior compartments the largest ; 

 aperture proportionately larger than in the last ; oper- 

 culum of four valves, the two upper slightly striated 

 transversely, the others smooth. Diam. up to i. 

 Common every where. * 



B. RUGOSUS. Mont, (not Lam. 23.) p. 8.Ch.f. 

 824 ?Dor. Cat. p. 25. t. 2. f. 10. LEPAS R. D. 

 p. 17. Lin. T. 8.^.25. t. l.f. 5. Turt. f. D. p. 

 76. An L. BOREALIS. Don. 5. t. 160.? An B. Ovu- 

 LARIS, Lam. 8 ? Suhcylindrical, usually divided into 

 six compartments by furrows which become broad to- 

 wards the top, where the shell spreads into angulated 

 points and is often as wide as at the base ; valves irregular 

 the post ones broader, sometimes wrinkled or striated 



* B. TINTINNABULUM. Da Cos. p. 250. Brug. p. 

 165. Lam.3. Mont. p. 10. LEPAS T. Lin. 13. 

 D p. 22 Turt. D. p. 75. fyc. fyc has no just 

 claim to be considered a native species, being only 

 taken from the bottom of ships arriving from wanner 

 climates. 



* LEPAS RADIATUS. Turt. D. Wood. G. C. t. 

 l.f. 7. cannot be considered either native or natu- 

 ralized, having only been found on the bottom of a 

 ship. 



