16 



GENUS BALANUS. 



Conical or elongated-conical, composed of six unequal 

 pieces or valves, closed at the sides upon a more or 

 less firm testaceous fiat base : shell open at the top, 

 operculum of four moveable valves. 



B. COMMUNIS. Pultney. Mont. p. 6. Dor. Cat. 

 t 2./. 12. LEPAS BALANUS, Lin. 1107. D. p. 14. 

 Pen. 4. p. 72. t. 37. f. 4. Don. t. 30. /. 1. 

 Turt. D. p. 77. Ch. f. 820. Born. t. 1. /. 4. 

 B. SULCATUS. Lam. 2. Brug. p. 1. 63. Strong, rug- 

 ged, cinereous-brown, compartments unequal and 

 frequently indistinct, composed of irregular and lon- 

 gitudinal striae or ridges ; conical, detached shells often 

 perfectly round at the base and sloping upwards; 

 aperture not large in proportion : operculum of four 

 valves, transversely striated, with a longitudinal furrow 

 on the two longest. Diam t at base, 1. I. Not 

 uncommon but local. 



B. VULGARIS. Da. Cos. p. 248. t. 17. /. 7. 

 List. t. 444. /. 87. List. Ang. 5. /. 41. LEPAS 

 BALANOIDES. Lin ?D. p. 16. Turt. D. p. 77. 

 Wood G. C. p. 44. t. 7. f. 3. Pen. 4. t. S7./ 5. 

 Don.t. 36. /. 2. Mont. p. 7. List. t. 444. /. 287. 

 Ch. f. 826. B. BALANOIDES. Brug. p. 166. 

 An B. OVULARIS ? var. Lam. 8? Subconical, some- 

 times much depressed, valves divided by a deep longi- 



