22 ON THE ECHINODERMATA OF THE 



coast of N. America from Labrador to New Jersey, and probably even as far south as 

 Cape Florida ( Wiirdemann, fide A. Agassiz) ; west coast of N. America to Vancouver. 



c. North of European Continent : Spitzbergen, Novaya Zemlya, Iceland, Faeroe 

 Islands, Scandinavian coasts, Britain. 



d. North of Asiatic Continent : Behring's Straits, Kamtschatka, Ochotsk Sea 

 (Brandt}. 



Description of the Illustrations of this Species on Plate II. 



Fig. 1. An example of the thinly-spined form. Abactinal aspect : natural size. 



2. The same specimen seen in profile : natural size. 



3. Portion of the test near the ambitus, showing the ambulacral and inter- 



ambulacral areas : magnified. 



