Bulla. 
MOLLUSCA. BRANCHIFERA. 
179. ^ alba . — ‘‘ Shell oval, oblong; slightly striated longi- 
tudinally ; entirely white ; crown umbilicate ; at each extremity 
three transverse punctured stria?.” 
Dr Turton, Zool. Journ. No. vii. 364. t. xiii. f. 6 — British Channel. 
Dr Turton adds, “ They are more elongated than the Bulla ampulla (the 
reference is evidently here intended for the B. striata of Lamarck, not to the 
true Ampulla), and essentially differ in having only three rather remote trans- 
verse strhe at each end, whereas on the latter shell there are seven or eight 
striae on the lower extremity, and none on the upper.” 
Shells probably concealed^ destitute qf‘ a cuticle^ and under 
the integuments. 
180. B. Shell smooth, with indistinct lines of growth ; 
suborbicular, depressed ; aperture expanded ; pillar short. 
Linn. Syst. i. 1 1 83. Bull. Dorset. 40. Don. Brit. Shells, t. ccxx. Mont- 
Test. Brit. 208. vig. ii. f. 1, 3 — Not common. 
Length 1 inch, breadth |ths, thin, pellucid, white ; apex simple ; body 
slightly involuted. Animal pellucid, white, with minute opake specks ; sto- 
mach of three testaceous plates. 
181. B. punctata. — Shell suborbicular, patulous, monihform- 
ly striated longitudinally. 
Adams., Linn. Trans, v. 2. t. i. f. 0, 8 — B. catena, Mont. Test. Brit. 
215. t. 7 . f. vii. — On the English coast, not common. 
Length about |th of an inch ; breadth rather less ; apex rounded, with a 
cavity exposing a volution. Montagu mentions “ a variety with a more 
transparent zone, taking in eight or ten of the cateine, which are more strong- 
ly defined ; the rest of the shell appears as it were frosted, and not so glossy, 
possessing a subumbilicus ; and the outer margin of the aperture, close to the 
body, is winged, or reflected a little, forming a depression or sulcus on that 
part.” 
182. B. emarginata. — Shell gibbous ; aperture emarginate ; 
pellucid, smooth ; lip subarcuated. 
Adams, Linn. Trans, v. 2. t. i. f. 9, 11.— On the English coast, rare. 
183. B. denticulata. — Shell white, pellucid, oblong, nearly 
equal, obtuse, smooth ; outer lip ending in a tooth retrally. — 
Perhaps only the young of B. aperta. 
Adams, Linn. Trans, v. 1. 1 . i. f. 3, 6 — Coast of Pembroke. 
184. ^.jlexilis. — Shell pellucid, horn-coloured ; apex white, 
opake, with a single volution. 
Laskey, Mont. Test. Brit. Supp. 168. Wern. Mem. i. 396. t. 8. f. 6.-— 
Dunbar, rare. 
Length half an inch, wrinkled ; flexible in a moistened state ; brittle when 
dry This shell probably belongs to the genus Sigaritus. 
