ovuLA. 497 



writers to be an adult Bulla, is very difterent from the 

 mature shell, and reminds one somewhat of a Succinea in 

 its general aspect. It is snow-white, extremely fragile, 

 more or less pellucid, has a short blunt spire of two or 

 three rounded turns and a capacious suboval aperture that 

 is very acutely contracted above, and is broad and pecu- 

 liarly open anteriorly. The outer lip is sharp and simple, 

 and as well as the inner one, is destitute of teeth. 



The animal is extremely variable in its colouring. The 

 mantle-lobes (which are only fully developed in the adult) 

 are sometimes bright orange, or yellow edged with orange, 

 and marked with broad transverse dusky bands, sometimes 

 mottled with brown, deep green and orange, without bands, 

 and occasionally of an uniform pinkish yellow hue, with 

 orange edges ; their surface is in some examples nearly 

 smooth, in others papillated. The head bears very long 

 tentacula ; the siphon is often much produced ; the foot 

 is very large, truncated in front, posteriorly extending far 

 beyond the shell, and terminating in a rather obtuse end. 

 The foot, head, and siphon are most commonly of a pale 

 orange colour. 



This pretty shell is diffused everywhere around the 

 British shores, and ranges from the verge of low water to 

 as deep as fifty fathoms. The number of old shells taken 

 surprisingly exceeds that of the young. It dates its place 

 in our area from the epoch of the coralline crag, and at 

 present ranges through the seas of Europe. 



OVULA. Brugierr. 



Shell egg-shaped, or sometimes spindle-shaped, its sur- 

 face polished, smooth, grooved or striated, whorls con- 

 volute, spire enveloped by the body-whorl, aperture 



VOL III. 3 s 



