202 PROCEEDINGS OF THE MALACOLOGICAL SOCIETY. 



of ^^aine it is abundant (Stinipson 114), e.g. at Eastport (Roper 103), 

 at Frenchman Bay (Blaney 12), at IS^orth Haven (Jackson 50), at 

 Boston (Stearns 113), where the var. imbricata, Lam., occurs. 

 Ap-gar's (4) statement, that P. lapilhis is abundant north of Cape 

 Cod, local south of the cape, represents the facts exactly. At the 

 point of Cape Cod it is found on the wharves at Provincetown 

 (Winckley 127, Rathburn 102). 



I am permitted to quote from a forthcoming work by Dr. Gi'atacap, 

 curator of the Brooklyn Museum, the following localities south of 

 Cape Cod: Nabsca Point, shores of Vineyard Sound, Cuttyhunk 

 Island, and Watch Hill, Rhode Island. On the Connecticut coast the 

 species becomes local at certain points onlj^, and does not occur east 

 of Stonington (Linsley 69), wliicli lies close to long. 72° W. and in 

 N. lat. 41° 30'. On Long Island it is abundant only in tlie extreme 

 north-east, at Montauk Point (Wheat 124, Smith &, Prime 111), 

 and is not recorded from anj^ other place. This is its extreme 

 southern range. Balch (8) does not give it in his list of the Mollusca 

 of Coldspring Harbor, nor does Perkins (97) in Ids catalogue of New 

 Haven Mollusca, and it does not even occur in Sanderson Smitli's 

 (104) catalogue of the Mollusca of Little Gull Island, which lies oil 

 Oyster Point, close to Montauk. 



Through the courtesy of Mr. Wheat, I am informed that a dead 

 specimen was once found at the Narrows on Staten Island, but this 

 was probably introduced among "oyster seed" from Connecticut. 

 Hubbard & Sanderson (49) do not include it in their catalogue of 

 the Mollusca of Staten Island. Dall's locality "New Jersey" 

 (Dall 22) is not to be taken as implying that P. lapilhis occurs on the 

 sliores of that State; "New Jersey" is merely his label, in the 

 particular paper referred to, for a stretch of coast from New Jersey 

 to Delaware and Long Island. Pord (34) does not include it in his 

 list of the shells of the New Jersey coast. Letson (66) gives 

 P. lapillus a place in his check-list of the Mollusca of New York, 

 avowedly on the authority of De Kay (30). De Kay's authority 

 becomes questionable when we observe his remark that P. lapilhis 

 " occurs along our coast from Cape Cod to Florida ". 



In conclusion, it will perhaps be interesting to direct attention to 

 the extremely limited range of the species on the American coast, as 

 compared with its extremely wide range on the eastern shores of the 

 Atlantic. Leaving Greenland out of the question, the range of 

 P. lapilhis on the American mainland is no more than 10 degrees of 

 latitude, from about N. lat. 51° to 41° 30'. In Europe, on the other 

 hand, it extends from N. lat. 71° to 37°, or 34 degrees of latitude. 

 Stated in miles, the range is in the one case about 690, in the other 

 above 2,340. If we take in Greenland on the one hand and Novaya 

 Zemlya on the other, the range in miles becomes 1,890 as compared 

 with 2,480. On the American shore the northward range of the 

 species is clearly restricted by the Labrador current, which flows 

 steadily southward from the Polar basin througliout the year, and 

 lowers the temperature of the water off East Canada, while the 

 estuary of the St. Lawrence is blocked with ice for four or five 



