34 (Bulletin of the Natural History Society. 
53. — LITTORIN A LITOREA.-(Linn.), Menke., (Periwinkle). 
Abundant in the waters of the Charlotte County coast. 
Northumberland Straits, Sir Wm. Dawson. South 
Shore of Prince Edward Island, J. F. Whiteaves 
(H) (I). 
This species is an important food-mollusc in England. It has been 
a disputed question as to whether it is indigenous to our shores or has 
been recently introduced from Europe. In an article by the writer in 
the “ American Naturalist ” for November, 1886, the evidence upon 
both sides is summed up and the conclusion arrived at that it is 
introduced, not indigenous. It was not reported by Stimpson (A), (B), 
nor by Verrill until very recently (K). It is not mentioned in any early 
lists of New England shells, has not been found in any Indian shell- 
heap nor in the post-pliocene deposits of Canada, and has not been 
found in Greenland or Labrador, in all of which situations, L. 
palliata, which is undoubtedly indigenous and which has almost the 
same habitat as L. litorea, does occur. There is absolutely no evidence 
to show that the shell existed in America before the advent of Europeans, 
and though the evidence tending to show that it did not exist here is 
necessarily of a negative character, it very strongly points to the latter 
conclusion. It is but right to add that Sir Wm. Dawson considers the 
shell indigenous to America. 
54. — LITTORIN A RUDIS.— (Maton), Gould. 
Reported by all observers as abundant upon the southern 
coast. 
Occurs with the following, chiefly upon bare rocks and the piles of 
wharves, while the two previous forms prefer the sea-weed and rocks 
covered by the latter. 
55. — LITTORIN A. TENEBROSA.— (Montagu), Gould. 
With the last. 
The form of this and the last species grade into one another. This is 
probably but a variety of the last. 
56. — LACUNA NERITOIDEA.— Gould. 
Grand Man an, Verrill (F). 
