THE MOUNT DESERT REGION 205 



Thais Bolten 

 T. (Nucella) lapillus (Linne). {Buccinum lapillus Linne, 

 1758, Syst. Nat. ; Purpura lapillus Gould, 1870, Inv. Mass., 

 p. 360, fig. 630.) The most beautiful snail of our coast; 

 occurs on the shore everywhere among the rocks. The variety 

 P. imhricata of Lamarck, with its sharp ridges, is found on 

 stones on the west side of the Island, generally hidden in 

 seaweed, and is always white. See On Some Varieties of 

 Thais lapillus in the Mount Desert Region, etc., by H. S. Col- 

 ton, Proc. Acad. Nat. Sci. Phila., 1916. Reported common 

 Maine to Connecticut. Common Bay of Fundy and Atlantic 

 coast of Nova Scotia ; Gaspe, 



Columbellidae 

 Columbella Lamarck 



C. (AsTYRis) ROSACEA (Gould). {Buccmum rosaceum Gould, 

 1840, Amer. Jour. Sci.; C. rosacea Gould, 1870, Inv. Mass., 

 p. 357, fig. 627.) This pink-tinged small form is dredged at 

 stations inside the Porcupines. Stations : D 14, 15, 22-24, 

 36, 38. Reported from Eastport to east of Block Island, in 

 6 to 29 fathoms. Sparingly distributed throughout entire 

 Canadian Atlantic region. 



C. (AsTYRis) DissiMiLis Stimpsou. (Proc. Boston Soc. Nat. 

 Hist., 1851, vol. 4, p. 114. 'Bay of Fundy.' Bnccinum zonalis 

 Linsley, 1845; Astyris zonalis Verrill, 1872.) A few were 

 taken with C. rosacea at D 27 in one dredging. Reported 

 from Penobscot Bay, Eastport Harbor, Grand Manan. 



Alectrionidae 

 Alectrion Montfort 

 A. (Tritia) trivittata (Say). (Nassa trivittata Say, 1822, 

 Jour. Nat. Sci. Phila.; Nassa trivittata Gould, 1870, Inv. 

 Mass., p. 364, fig, 632.) This active animal, with a shell quite 

 unlike any of our other snails, is common everywhere on mud 

 bottom from Eastport, Me., southward. A piece of meat sunk 

 to the bottom will be covered in a short time. The 'mud snail.' 

 Bay of Fundy, Atlantic Coast of Nova Scotia, Bale des 

 Chaleurs. 



