THE ECONOMIC MOLLUSCA OF ACADIA. 
31 
(b) In Acadia ; — (in N. B.) Grand Manan, low- water 
mark to forty fathoms, Stimpson. L’Etang Harbor and 
Passamaquoddy Bay, Ganong. Particularly large, fine and 
abundant about low-water mark at Hospital Island, Passa- 
maquoddy Bay; (in N, S.) Annapolis Basin, abundant, 
VerJcruzen. Halifax Harbor, Jones. LaHave Bank, Jones 
(on authority of Verrill.) Sable Island, Gould (on authority 
of Willis). Not yet reported from Prince Edward Island 
or the Gulf of St. Lawrence. Probably rather common in 
sand and mud on the Bay of Fundy coast, and perhaps less 
so on the Atlantic shores. May be very rare or quite wanting 
in the Gulf of St. Lawrence. 
Habits. This is a very striking shell, and one easily distinguished 
from all others by its ten raised revolving ribs. The ground color is a dul| 
fulvous or yellowish-red, but the ribs are darker. Of these there can 
always be counted nine, generally 
ten and rarely more on the lower 
whorl, of which only two, rarely 
three, revolve on the upper 
whorls. The ribs being large 
and very solid, give the shell a 
handsome fluted appearance. 
The lower end tapers to a canal. 
It is about three inches in length, 
though frequently somewhat 
larger. It seems to prefer mud 
and sand bottoms in rather shal- 
low water on our coasts, rather 
than rocks in deep water as 
Gould suggests. In L’Etang 
Harbor it is often dredged with 
mud, but occurs in greatest per- 
fection and beauty in the clean 
sand and clear water about low- 
water mark, at Hospital or Little 
Hardwood Island in Passama- 
quoddy Bay. There it lives half- 
burrowing in the sand, with only 
its spire projecting at times, and Fig< 3 __ Fusns decemcostatus. 
leaving deep furrows behind as si/e. 
it works its way along. Specimens from this locality are very clean 
and bright and show no trace of the parasitic growths which 
Natural 
