SEA-FISHERIES LABORATORY. 213 



Jersey ami has been figured, probably from the coast of 

 Normandy, by Milne Edwards in the plates of Cuvier's 

 " Ilegne Animal " (Edition de Disciples, Plate VIII., Fig. 

 1), where it may be recognised by its characteristic gills. 

 From the records of ^4. marina, made by Scandinavian and 

 other naturalists who have examined specimens from 

 northern seas, it would appear that the littoral variety is 

 the only one with which they are acquainted. 



Distribution. 

 Arenicola marina has been recorded from both sides 

 of the Atlantic, e.g., from the shores of Western Europe, 

 Norway, Spitsbergen, North Siberia, Iceland, Greenland, 

 and along the northern coast of America from the Bay of 

 Fundy to Long Island."" Latitude 40° N. marks approxi- 

 mately the southern limit of A. marina on the Atlantic 

 shores. South of this it is replaced on the American 

 coast by A. cristata, and in the Mediterranean by A. 

 da par edit and ^4. cristata. 



External Characters. 



The description of the external characters of 

 Arenicola will be better understood after a brief reference 

 to those of some other Polychaet, such as Nereis, in which 

 the segmentation is more clearly shown. 



At the anterior end of Nereis is the distinct " head," 

 at the posterior end the " tail," while the intervening 

 portion is sub-divided by a series .of shallow grooves into 

 a number of segments which are practically identical in 

 their external characters except in size. Each segment 

 bears laterally a pair of muscular out-growths provided 

 with bundles of bristles, or setae, and with certain sensory 



* It is also reputed to occur on the shores of Vancouver Island 

 and in Angra Pequena Bay (West Africa). 



