120 



BALJ?NOPTERID,E. 



h. Skull of adult. Grreenland. Professor Eschriclit's Collection. 



c. Baleen of skull h. Greenland. Professor Eschricht's Collection. 



d. Skeleton. Greenland. Professor Eschriclit's Collection. 



The cervical vertebrae are all free. The second cervical vertebra 

 has two very large, thick, converging lateral processes, as long as 

 half the diameter of the body of the vertebra ; the third, fourth, 

 fifth, sixth, and seventh have elongated slender superior lateral pro- 

 cesses which bend rather downwards, and the sixth and seventh 

 rather forwards ; the fourth and fifth have a very short rudimentary 

 inferior lateral process, which is smaller on the left side ; the other 

 vertebrae are without any. 



The upper part or the spinous process of the second vertebra is 

 very large and convex, covering this part of the next vertebra. — 

 Gray, P. Z. S. 1847, 92. 



Fiff. 15. 



Atlas vertebra of Mer/apiera lonf/imanft. 

 Extreme width 20 inches ; height 13 inches. 



Var. 1. The cervical vertebrae are all free. The second cei-vical is 

 very thick ; the third, fourth, fifth, sixth, and seventh are thicker and 

 of nearly equal thickness, the seventh being rather the thickest. 

 The upper lateral processes are developed and nearly equal in all of 

 them, those of the third and fourth being directed backwards, the 

 fifth straight out, and those of the sixth and seventh directed 

 backwards at the end. The lower lateral processes are generally 

 wanting ; the fourth and fifth vertebrae have a rudimentary process 

 on each side ; the processes are of very unequal length on the two 

 sides of the same vertebra, the largest being not more than an inch 

 and a half long, and the rest mere rounded tubercles. The breast- 

 bone is irregular subrhombic, with a large central perforation. 



