The Nautilus. 



Vol. XVII. MARCH, 1904. No. 11. 



HELIX HORTENSIS IN NEW ENGLAND. 



BY REV. HENRY \X. AVINKLEY. 



The following is a suggestion. I cannot say that I am convinced 

 that it is a proof, but 1 offer these thought.s for what they are worth. 

 We must associate //. hortensis with northern European forms rather 

 than with the American land shells. Its distribution in New Eng- 

 land is most singular, limited as it is to widely separated spots, 

 mostly .^mall islands of the east coast. It certainly cannot have had 

 the same migration as Polygyra or Pyramidula or it would be dis- 

 tributed as they are. Undoubtedly at the close of the glaciiil period, 

 the American types worked north and east into New England ; but H, 

 hortensis was not one of them. That it came from Europe is evident. 

 Commerce-voyages of Norsemen or other explorers have been sug- 

 gested. This theory becomes absurd when one examines the locali- 

 tfes where H. hortensis lives. These places are not ports and never 

 have been. Some of them are the last places a man would land, not 

 the first. Let us now ask the question of an earlier migration. 

 Circumpolar species exist. Other forms common to Europe and 

 America would make an interesting study. That there was a |)re- 

 ghacial period when forms migrated around the northern regions is a 

 settled fact. Did H. hortensis come then and survive? The writer 

 has been much interested in the glacial theory, and has done some 

 field work on tjie New England area. That the glacier covered all 

 of New England is an accepted fact, but when we say all, is there 

 not a chance for exceptions. Along the southern coast we may point 



