6q 



Canadian Arctic Expedition, 1913-1918 



regard inside the same species and sex, and according to age (see Sars (1896), 

 p. 71, Tab. XII). 



Explanation of Text-Figures 



(All the figures, except \d, c, are original, freehand drawings after alcoholic specimens, viewed under the 



microscope.) 



Fig. 1. Telson of Lepidurus arcticus Pall, (see also Olofsson, 191S, figs. 18-19.) 



a. Dorsal view. About x 50. Animal (female) 12 mm. long. Teller, Alaska. 



In natural position and spread out. About x 50. Animal f female) SJ- mm. long. 



Martin point, Alaska. 

 Outline of telson, without the spines. About x 50. Animal (female) 18 mm. 



long. Martin Point, Alaska. 

 Telson and cercopods of about l-J- mm. long, larva from N .E. -Greenland (after 



Brehm). 

 Telson and cercopod of about 2 mm. long larva from Filefjeld, Xorwa\' (after 



Sars). 

 Telson and cercopod of .3 mm. long larva from Bernard harbour, N.ft'.T., July 



3,1916. About X 100. 

 About X 50. Animal (female) 7 mm. long. Bernard harbour, X.W.T., August 



16, 1915. 

 About X 50. Animal (female) 12 mm. long. Bernard harbour, X.W.T., October 



6, 1915. 



