THE SESSILE BARNACLES. 



209 



Whether the American area of the species is continuous in the 

 north with the European is not positively known, but from what we 

 know of the limitations of the species, such continuity at the present 

 time does not seem likely. 



In the Pleistocene this was an abundant barnacle in northern 

 Europe and Canada, New Brunswick, and Bangor, Maine. LinnEeus 

 was the first to notice the species. He found it in the pleistocene 

 deposits of Uddevalla, but in the text of his work (p. 198) he seems 

 to have taken it for the Uddevalla form of B. balanus, and not a 

 distinct species. 



EUROPEAN. 



AMERICAN. 



