MANGELIA. 457 



that precedes the formation of a canal. The incipient 

 beak is scarcely at all recurved. The pillar lip is broadly 

 reflected, and the longer portion, the lower end, of it is 

 nearly straight. The breadth of an individual that mea- 

 sured rather more than half an inch in length, was two 

 lines and a half. 



In the large and greatly produced variety Ulideana, the 

 aperture is small, and only occupies three-eighths of the 

 total length ; the ribs, which are usually few, distant, and 

 slanting, are strong and remarkably prominent, and the 

 suture is rather more oblique than usual. The type of 

 this form (pi. OXII. f. 5), for the loan of which we are 

 indebted to Mr. Thompson, is of a reddish orange-brown, 

 with the spiral sculpture somewhat coarse, and the body 

 scarcely filling one half of the dorsal length. 



The animal is white. Its head is rather large and 

 broad. The tentacula are linear and produced. Tlieir 

 apical portion is not equal to the thickened eye pedicles, 

 and is somewhat clavate and obtuse ; the eyes are placed 

 on prominent bulgings at a little less than two-thirds of 

 the height of the tentacle. The foot is wide, but not so 

 expanded as in turricula. Its frontal margin is truncated 

 and has the angles subauriculated ; its caudal extremity is 

 truncate and slightly emarginate. The operculum is borne 

 very near the extremity. The siphon is produced much 

 beyond the canal. 



This shell is more common in the South than in the 

 North, but has a wide diffusion. It is rarely taken in 

 quantity. It ranges through the laminarian and upper 

 part of the coralline zones, though seldom found alive 

 deeper than twenty fathoms. It frequents gravelly 

 ground. It is found sparingly all round the English and 

 Irish coasts, more rarely on the shores of Scotland. We 



VOL. 111. 3 N 



