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 Buccinum. This species 
is not quite so common as B. unda- 
tum, but it is often found asso- 
ciated with it. At Eastport and 
Sipho Stimpsoni. 
Chrysodomus decemcostatus. 
Bar Harbor it is abundant just 
below low-water mark. 
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 
