ARCTIC SEA TO THE WEST OF GREENLAND. 53 



retarding the progress of growth-characters and in the maintenance of the youthful or 

 more simple form. The spinulation of the paxillac is similarly subject to variation. 



Distribution. 



a. Greenland : Hare Island, Waigat Strait, lat. 70 30' N., 175 fms. (' Valorous ' 

 Exped.). 



b. North of American Continent : Melville Island, about lat. 74 47' N., long. 

 110 48' W. (Parry's Exped.) ; Assistance Bay, 7-15 fms. (Penny's Exped.) ; New- 

 foundland (Sars) ; Bay of Fundy, 50-60 fms. (Stimpson) ; Maine. 



c. North of European Continent : Spitzbergen (LutJcen) Barents Sea, lat. 76 

 58' N., long. 45 40' E., 110 fms. (' Willem Barents ' Exped.), the most northern locality 

 on record ; Finmark ; Scandinavian coast. 



Description of the Illustrations of this Species on Plate III. 



Fig. 17. Abactinal aspect of the animal: natural size. 



18. Actinal aspect of the same specimen : natural size. 



19. Portion near the middle of a ray, actinal aspect : magnified. 



20. Portion near the middle of a ray, abactinal aspect : magnified. 



