1908.] 



Allen, The North Atlantic Right Whale. 



329 



thickened at the posterior extremity. The right pelvic bone, measured 

 along the curvature of the dorsal margin, has a length of 450 mm.; the left 

 one a length 435 mm. Each pelvic bone had attached to it a vestigial 

 femur, a flattened bone, 135 mm. long, 58 mm. wide, and 10 to 28 mm. 

 thick, parallel-sided for about half the length, with one entire side straight, 

 the other sloping at an obtuse angle. Unfortunately thet were separated 

 from the pelvic bones before their position and manner of attachment was 

 noted. One of the pelvic bones with its vestigial femur is shown in the 

 accompanying text figure. 



The pelvic bone and femur in Eubalcena glacialis greatly resembles 



Fig. 1. Right pelvic bone, inner view, and vestigial femur of the large Amagansett Whale. 



these bones in Baloena mysticetus, as described and figured by Struthers. 1 

 In each species there is evidently a wide range of individual variation in 

 respect to the size and form of these bones, as shown in the eleven specimens 

 of B. mysticetus described by Struthers, and by the several specimens of 

 E. glacialis described and figured by Guldberg, and the two described in 

 the present paper. These variations affect the curvature and thickness, 

 as well as the general size, of the pelvic bone and the size and form of the 

 femur, which possibly may in some cases be wanting, as was probably the 

 case in the Provincetown specimen above described. 



1 On the Bones, Articulations, and Muscles of the Rudimentary Hind-Limb of the Green- 

 lane! Right Whale (Balcena mysticetus). By John Struthers, M. D. Journ. Anat. and Phvs 

 XV, 1881, pp. 141-176, 301-321, pll. xiv-xvii. 



