BULLA. DIPPER. 25 



from B. aporta, in its elongated and ear-shaped form : 

 length three quarters of an inch ; breadth half an inch. 



When alive, the animal completely envelops the shell, 

 from which circumstance it naturally falls into this fc... 



Western coasts, Dublin bay, Scotland, v. v. 



14. Bulla tentaculata. Armed Dipper. 

 Linn. Trans, xi. pi. 12. f- 5, 6. 



Shell so extremely similar to the B. haliotoidea, that 

 Montagu observes no distinction can be conveyed by de- 

 scription or figure, except that it is rather more depressed 

 and opake. To the animal alone, therefore, must we refer 

 for the actual identity of each, which in their structure i^ 

 materially and essentially different. The animal of B. ha- 

 liotoidea is represented at fig. 6, in the Vignette to the se- 

 cond part of Montagu's Testacea Brit&nnica ; and that cf 

 B. tentacuiata as above quoted. 



At the salt-rock, in the estuary of Kingsbridge, Devon : 

 rare. 



15. Bulla fiexilis. Flexible Dipper. 

 Laskey, Wern. See. i. pi. 8. fig. 6. 



Shell oval, transparent, horn-color, flexible when \p?t, 

 very brittle when dry, white and opake at the crowr, 

 where there is a single oblique volution. In shape and the 

 form of the involution it exactly resembles B. haliotoidc , 

 but is much more distinctly wrinkled : length half an inclx. 



Found by Captain Laskey, at Dunbar : very rare. 



16. Bulla Plumula. Feather Dipper. 

 Montagu, pi. 15. f. 9, and Vignette 2. f. 5. 



Shell oblong-oval, fiat, thin, transparent, concentrically 

 wrinkled, with two or three ray-like impressions from the 

 base to the crown : color yellowish-white, tinged with 

 brown at the base, the other end folded into a single veiy 

 minute volution : aperture extending over the whole shell, 

 slightly turned in at the crown to form the very minute vo 

 lutSon : length half an inch ; breadth nearly a quarter. 



On Milton sands, Devon : very rare. v. m. 



\7. Bulla membranacea. Membranous Dipper. 



Linn. Trans, xi. pi. 12. f. 4. 



l chcll oval, flat, extremely thin and delicate and some- 

 D what 



