il8 BULLID/E. 



Shell forming a short cylinder, or oblong, broader in the mid- 

 dle, and less solid than in the last species, semitransj^arent, and 

 decidedly glossy : sculpture, nnmeroiis and close-set but ex- 

 tremely fine and slight spiral strioe, which can only be de- 

 tected by the aid of a strong magnifier : ejndermis, a pellucid 

 creamy film : colour white : mouth more open than in C 

 cylindracea, although having the same shape : outer lip gently 

 curved throughout ; it is higher at the top than in the last 

 species, and at the outer corner it recedes or slopes more 

 abruptly ; inner comer obhquely incurved : ape.v twisted 

 (not contracted) ; it is encircled by a strong and angulated 

 rim, and concave in the centre, with a minute perforation in 

 some specimens : inner lip forming at the upper end a thick 

 fold, which is reflected on the apex and usually covers the 

 perforation ; it is conspicuous, but thin, in other parts : pillar 

 short, broad, curved and twisted to the left, with an obscure 

 plait. L. 0-35. B. 0-175. 



Habitat : Fine sand^ iu 84-95 f._, about 25 miles 

 N.X.W. of Unst, with Limopsis aurita and other rare 

 mollusca. It is one of our post-glacial fossils, and has 

 been found at Greenock (Stewart Kerr, fide Brown), 

 Paisley and Lochgilphead (Crosskey), Dalmuir (Robert- 

 son), and Annochie in Aberdeenshire (Jamieson) ; 

 Mammaliferous Crag near Norwich (Witham, ^f/e S. 

 Wood as Bulla cylindracea^ var. monstrosa) ; Norway 

 2-40 feet (Sars). Its existing range is arctic and high 

 northern, and comprises Norway, Iceland, Spitsbergen, 

 Greenland, and North-east America ; west coast of 

 North America (P. Carpenter) : depths 10-160 f. The 

 most southern limit appears to be Bergen. 



This lives with C. cylindracea ; and its movements 

 are equally slow. In one Norwegian specimen the 

 colour of the epidermis is brownish-yellow, as in 

 the other species. I have figured the tongue, from a 

 drawing kindly made for me by my late friend ^Ir. Alder. 



It is the Bulla triticea of Couthouy, and B. corticata 

 (Beck) of Moller. 



