BULLA. 479 



concealed under the skin of an animal whose diameter is 

 nearly double its own. 



hydatis. 17. Shell rounded, pellucid, and slight- 

 ly striated longitudinally; apex umbilicated. 



Bulla Hydatis. Lin. Syst. Nat. p. 1183. Schroeter Einl. 



i. p. 173. Chemnitz, ix. part 2. p. 27. t. 118. f. 1019. 



Gmelin, p. 3424. Bruguiere in Eric. Method, p. 374. 



Montagu Test. p. 217. Vign. 1. f. 1 to 5. Donovan, \u. 



t. 88. Ma ton and Racket in Lin. Trans, viii. p. 123. 



Dorset Cat. p. 43. t. 23. f. 10. 

 Bulla Navicula. Da Costa Brit. Conch, p. 23. 1. 1. f. 10. 

 Bulla hyalina. Gmelin, p. 3402. 

 Bulla papyracea. Ulysses s Travels, p. 456. 

 Bulla Physis, Var. Schreibers Conch, i. p. 87. 

 Bulla, No. 1. Schroeter Einl. i. p. 187- 

 Gualter, t. 13. f. D D. Martini, i. t. 21. f. 199- 

 Inhabits the Mediterranean Sea. Linnceus. Bay of Tarentum. 



Ulysses. Coasts of Britain. Da Costa, fyc. 

 Shell often an inch long and three quarters broad, rather 

 oval, sub-pellucid, brittle, of a greenish or yellowish horn- 

 colour, and in shape more like B. Naucum than B. aperta, 

 to which Gmelin has compared it. The body of the shell is 

 tumid, and there is no external volution, but in its place is 

 an umbilicus. Linnaeus has described B. Hydatis to be 

 rounded, whereas it is oval, and Gualter's figure, to which 

 Linnaeus has referred, is of a more spherical form than any 

 other of the figures above quoted, but there does not ap- 

 pear to be much doubt of their belonging to the same species. 



ampulla. 18. Shell rounded, opake, dotted in 

 waves ; apex umbilicated. 



Bulla Ampulla. Lin. Syst. Nat. p. 1 1 83. Martini, i. p. 



279 and 280. t 21. f. 188 to 193. Born Mus. p. 202. 



Schroeter Einl. i. p. 174. Bruguiere in Erie. Metho- 



dique, p. 371. Lamarck Syst. des Animaux, p. 90. 

 Bulla solida. Gmelin, p. 3439. 

 Lister Conch, t. 713. f. 69, and t. 1056. f. 8. Rumphius, 



t. 27. f.G. Petiver Gaz. t.99- f. 14, and Amb. t. 9. 



f. 19. Gualter, 1. 12. f.E. Seba, iii. t. 38. f. 34 to 43. 



Knorr, ii. t. 8. f. 1 to 5, andt. 17. f. 6; and vi. t. 21. f.2. 



Regenfuss, t. 5. f. 58, and t. 8. f. 21. Favanne, t. 27. 



f. F 6. Enc. Method, t. 358. f. 3, a and b. 



