SHE SES WiehHOwUl CANALS 213 
that is, it has no eanal, and it is closed by a thin 
brown, circular operculum. 
Trichotropis borealis, Br. & Sby., the Northern 
Hairy-shell. This species has a_ short spire, 
strongly shouldered whorls, which are hairy on the 
ridges, and a distinct umbilicus. There are many 
varieties, and the average length is about one inch. 
This species inhabits the Arctic waters on both 
sides of the continent. 
Trichotropis cancellata, Hds., the Checked 
Hairy-shell, has a longer spire than the last, con- 
sisting of about seven whorls. The epidermis, 
which is somewhat hairy, is light brown or gray- 
ish, and the aperture is often pink. It ranges from 
Alaska southward to Vancouver Island, where it 
is said to occur abundantly. 
Anaplocamus borealis, 
Dall, the Northern Ana- 
plocamus, Figure 230. This 
singular shell, which much 
resembles some that live in 
fresh water, comes from 
considerable depths off the 
coast of Alaska. It is bluish 
white, but has an_ olive- 
brown epidermis. 
Caecum californicum, 
Dall, the California Tube- Fig. 230, x 7 (*) 
shell. This singular species differs much from 
any that have gone before. The shell is a little 
white tube, 38mm. long, slightly curved, and show- 
