156 On the Mollusca of Long Island. 



Littorina Peconica. Animal dark grey to black above. 

 Head and upper surface of tentacles jet black. Tentacles about 

 quarter the length of the shell, blunt, bearing the black eyes 

 at their outer bases on bulgings of a lighter color. Foot half to 

 two-thirds the length of the shell, translucent white below, 

 with the anterior edge opaque white; rounded at both ends, 

 and grooved below, more distinctly than the preceding. When 

 the shell is closed, the dark upper surface, showing through 

 the transparent operculum, gives the appearance of a yellow 

 centre, formed by the attachment of the operculum, nearly sur- 

 rounded by a wide black band ; and this affords an easy method 

 of distinguishing this species or variety from the preceding, in 

 wbich, when closed, the operculum appears uniformly yellow. 

 The shell is indistinguishable from the preceding, presenting 

 almost all the varieties of color and markiiig ascribed by Gould 

 to L. palliata. Found with tlie preceding on and under sea- 

 weed, but much more abundant. 



37. Lacxma vincta Turion. Littoral and laminarian. Mode- 

 rately abundant. The variety fusca is about as abundant as 

 the striped variety, but appears to attain a larger size. The 

 animal has a foot about two-thirds the length of the shell, 

 rounded at both ends, not very narrow, dull white below. The 

 white edge of the operculigerous lobe, with its lateral wings, 

 forms a fringe around the posterior two-thirds of the foot. The 

 tentacular filaments of the operculigerous lobe are about half 

 as long as the tentacles. Tentacles white, long and pointed, 

 bearing the black eyes on very short pedicels at their outer 

 bases. Upper surface of head reddish-brown, extremity of 

 muzzle much lighter. Upper surface of body, and operculige- 

 rous lobe, white, dotted with grey. Specimens taken in Novem- 

 ber, feeding on green algse, had all the upper surface, except 

 the back of the head and foot, light green, attaining a bright 

 emerald green at the edges of the operculigerous lobe, near the 

 operculum. The shell also, in some specimens, was distinctly 

 green in some parts by transmitted light. The shell is generally 



