ANATOMY OF MEGAPTERA LONGIMANA. 119 



are the free ends of the four intervening processes in a gradually 

 increasing line backwards ; the second 1| inch less projecting 

 than the axis, the 6th only a little less projecting than the 7th. 



Another differential character of the superior transverse pro- 

 cesses of Megaptera is their straightness. In B. musculus they 

 curve upwards, so as to give the ring a decidedly concave upper 

 boundary ; in Megaptera they are almost straight from where 

 they leave the pedicle, with a little concavity at their outer end 

 only. The 7th begins to show a little general concavity. This 

 straightness is seen also on the upper aspect, though with less 

 definite outline, and contrasts with their convexity in B. mus- 

 culus. 



In regard to the size of the space between the upper and 

 lower processes, it is seen in Table V. to be about the same in 

 both, a little less in Megaptera. The distance between the 

 ends of the two processes of the 3rd and 4th vertebrse is 5 J and 

 6 inches. The ends of the upper processes are on a plane pos- 

 terior to those of the lower, to the following extent axis, 2 

 inches ; 3rd vertebra, 1 J ; 4th vertebra, 1 inch. In B. mus- 

 culus they are on the same level, having to meet externally ; 

 but on the 6th, as the lower process stops short, the outer end 

 of the upper process is on a plane somewhat anterior to the end 

 of the lower process. In the foetus of Megaptera, Eschricht 

 found the soft tissue completing the rings behind the axis to be 

 fibrous. 



The comparison of the transverse processes in B. musculus 

 and Megaptera would seem to show that the presence of com- 

 plete processes, forming rings, is not in adaptation to the pro- 

 tection of the great vascular rete that occupies the space, but 

 for the attachment of ligaments and muscles. 



Articular Processes of the Five Posterior Cervical Verte- 

 brce. The measurements in Tables II. and III. show the much 

 greater width apart of the articular processes in Megaptera 

 than in B. musculus, the distance averaging about 11 to 11 J 

 inches in Megaptera, in B. musculus about 9 to 9|, the 

 measurements taken from the outer edge of the processes. 

 The great increase (going forward) in width apart between the 

 processes begins in both at the 5th dorsal, owing to the turning 

 outwards of the processes ; obtains its maximum on the 1st 



