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, 

 Verhruzen. 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 sliell, and one easily distinguished 

 from all others by its ten raised revolving ribs. The ground color isadul}, 

 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 beaut}' 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 -F«ms decemcomtm. 

 leaving deep furrows behind as si7e. 

 it works its way along. Specimens from this locality are very clean 

 and bright and show no trace of the parasitic growths w^hich 



Natural 



