BULLA. 497 



Volvaria bulloides. Lamarck Syst. des Anim. p. 93. 

 Lister Conch, t. 714. f. 70. right hand figure. 



Inhabits the coasts of" Britain. Lister, &c. 



Shell about eight lines long and three broad, white, smooth, 

 with the aperture extending through the whole length, very 

 narrow, and a little dilated at the base, It differs from the 

 foregoing species not only in size, but also in having the 

 aperture much narrower, and in the want of stria? at the two 

 ends. Though the description, taken from Schroeter's 

 Einleitung, is singularly erroneous respecting the aperture, 

 it is obvious that Gmelin's B. Oliva was constituted entirely 

 from Lister's figure of this species. 



UMBILICATA. 58. Shell oblong-oval, involuted, 

 minute, rounded and umbilicated at the 

 apex. 



Bulla umbilicata. Montagu Test, p. 222. t. 7- f. 4. Ma- 

 ton and Racket in Lin. Trans, viii. p. 129. 

 Inhabits the sea it) Falmouth Harbour. Montagu. 

 Shell one eighth of an inch long, and half as broad, white, 



and differs from B. ci/lindracea in being less cylindrical, and 



broader in proportion to its length. 



retusa. 59. Shell sub-cylindrical, involuted, mi- 

 nute, striated longitudinally on the upper 

 part ; apex truncated and umbilicated. 



Bulla retusa. Maton and Racket, in Lin. Trans, viii. p, 



128. 

 Bulla truncata. Adams in Lin. Trans, v. t. 1. f. 1 and 2. 

 Montagu Test. p. 223. t. 7. f. 5. 



Inhabits the coast of Pembrokeshire, Adams, West of Eng- 

 land. Montagu. 



This species has the habit, and is of the same size as B. um- 

 bilicata, but differs in being truncated at the apex, in being 

 striated longitudinally on the upper part, and in having the 

 aperture most contracted in the middle. 



obtusa. 60. Shell cylindrical, involuted, with the 

 spire somewhat prominent. 



Bulla obtusa. Montagu Test. p. 223. t. 7. f. 3. Maton 

 and Racket in Lin. Trans, viii. p. 128. Dorset Cat. p. 

 44. t. 18. f. 14. 



Bulla Regulbiensis. Adams's Micros, p. 64.0. t. 14. f. 28. 



Walker's Minute Shells, fig. 62. 

 vol. i. 2 k 



