GASTEROPODS 



393 



These are prominent revolving ribs or keels upon the body-whorl, the 

 upper one being the largest, the others diminishing in size toward the 

 base of the shell. Upon the upper 

 whorls but two of these circling 

 keels appear. The lip is plain, but 

 somewhat modified by the termi- 

 nation of the ribs. The columella 

 is arched above ; the canal pro- 

 duced (sometimes to the left). The 

 color without is dull ashen-white 

 to horn ; within, pure white. The 

 operculum is small, with a termi- 

 nal nucleus. The animal is the 

 same as Huccinum. This species 

 is not quite so common as B. undu- 

 tunij but it is often found asso- 

 ciated with it. At Eastport and 



Chrysodomus decemcostatus. 



Bar Harbor it is abundant 

 below low-water mark. 



just 



Sipho Stimpsoni. 



GENUS Sipho 



S. Stimpsoni. One of the most 

 graceful of the larger shells of our 

 eastern coast. It is almost identical 

 with the S. islandicus of northern 

 European waters, and for a long time 

 was considered to be the same species. 

 S. Stimpsoni is not found south of 

 Cape Cod, except possibly in deep 

 offshore stations. North of that point 

 it ranges to Newfoundland, but it 

 has enjoyed the reputation of being 

 a rare shell and has been greatly 

 prized by local collectors in conse- 

 quence. It is, in fact, not rare to 

 any one who is provided with a dredge 

 and rope enough to enable him to use 



