ALEXIA. 173 



Auricula denticulate DE!VAY, N. Y. Moll. p. 58. pi. v. figs. 91, 93, (excl. Valuta 



denticulata Mont. et. syn.) nee MOXTFORT. 

 Melampus denticulatus STIMPSON, Shells of N. E. p. 52, (absq. desc.) excl. syn. 



Mont. 



Jfelampus borealis COXRAD, Am. Journ. Sc. vol. xxiii. p. 345, (1833). 

 Akxia myosotis H. et A. ADAMS, Gen. Rec. Moll. vol. 2, p. 241, (Sept. 1855,) 



absq. desc. 

 PFEIFFER, Mou. Auric. Viv. p. 148. 



DESCRIPTION. 



Animal short, about one half the length of the shell, 

 dirty white, darker on the head and tentacles ; eyes black, 

 placed at the inner base of the feelers ; feelers quite short, 

 wrinkled, bulbous at tip, sufficiently dark to be visible 

 through the thin shell when the animal withdraws itself; 

 head continued beyond the tentaculae into an obtuse, 

 short, bilobed snout; the shell is carried horizontally on 

 the animal's back ; the obtusely pointed posterior termi- 

 nation of the foot is just visible beyond the shell ; the 

 animal is sluggish in its movements. See plate. 



Shell elongate-oval, thin, semi-transparent, smooth and 

 shining ; dark horn-color, with a narrow reddish sutural 

 line ; spire produced with an acute apex ; suture distinctly 

 impressed ; whorls from 7 to 8, the upper ones rather con- 

 vex, the last one elliptically ovate, equalling f of the shell's 

 length ; aperture subvertical, about | the length of the shell ; 

 peristome thin, sharp, sometimes furnished with tooth-like 

 folds on its inner side ; its basal termination appressed to 

 the shell, slightly reflected over a minute perforation, and 

 turning upwards till it blends with the columellar fold, 

 which winds into the aperture ; the parietal wall is fur- 

 nished with a white, transverse, thin, and sharp denticle, 

 and a second smaller, much less prominent one, placed 

 above it. 



Greatest diameter 4, length 8 millimetres. 



Geographical Distribution. Found in Massachusetts 

 Bay, (Gould, Stimpson, Tufts) ; New York harbor, (De- 



