LEPAS. 33 



** With Conical Shells. 



TURBAN ACORN. 



PI. 4. Mrs. Robinson. 



2. Lepas Diadema. L. testa subconica, lobis sex elevatis quadripartitis, 

 operculo membranaceo bidentato. Mull. Zool. Dan. p. 550. No. 3024. 

 Linn. Gmel. p. 3208. Fabric. Fr. Groenl. p. 425. 



Shell subconic, with six raised four-parted valves ; operculum membra- 

 naceous and bidentate. 



Testa subrotunda, sexlobata, sulcata. Linn. Syst. Nat. ed. 12. p. 1108. 



Balanus, testa subcylindrica, valvulis longitudinaliter sulcatis, costis 

 decussatis, radiis transverse striatis. Brug. Encycl. Meth. Hist. Nat. 

 torn. 6. p. 171. 



Pediculus ceti. Ellis, Phil. Trans, vol. 50. t. 34. f. 7. 



Lister, Conch, t. 445. f. 288. Gualt. Test. t. 106. f. Q. Walch. Naturf. 

 8. t. 4. f. a. b. c. Born, Mus. Cess. Test. 1. 1. f. 5, 6. Da Costa, Brit. 

 Conch, p. 251. t. 17. f. 2. Encycl. Method, pi. 165. f. 13, 14. Donov. 

 Br. Shells, t; 56. f. 1, 2. Mont. Test. Brit. p. 13. Linn. Trans. 8. 

 p. 27. 



The Lepas Diadema is composed of six valves, which, 

 with their intermediate spaces, divide the shell into 

 twelve, unequal, triangular compartments. Six of these 

 divisions are formed of strong longitudinal ribs, from 

 four to six in number, which diverge from the apex 

 towards the base of the shell, and are striated trans- 

 versely. The other compartments, though they have a 

 polished surface, are finely striated. The interior is 

 funnel-shaped, being much wider at top than at bot- 

 tom ; it exhibits six divisions, formed by as many 

 bands, which correspond with the external valves. The 

 bottom is divided into eighteen striated partitions, which 

 project a little within the opening of the shell, and are 

 finely toothed, for the purpose of adhering more firmly 

 to the back of the whale. These divisions are generally 



VOL. I. D 



