328 



SIR RAT LAXKESTER ON THE 



[Apr. 7, 



is carried very far in Erinaceus. Whether the existence of an 

 inferior portion or inferior transverse process should be regarded 

 as a primitive feature of all these vertebrae in Mammalia is not 

 clear. It certainly seems to belong as an original element of 

 structure to cervicals 3, 4, 5 and 6 — to be increased greatly 

 in size on cerv. 6 in most groups, and sometimes to practically 

 disappear from the other cervicals whilst remaining there. 



iKAPI. 



1 r s . I , 



Text-fig. 66. 



OK API. 



Dors. 2. 



fr6'.A_ 



OKAPI. 



POSTERIOR FACE. 



ITEPJOR FACE. 



POSTER J OR FACE. 



View of the articular surfaces which connect dorsal 1 and dorsal 2 of the Okapi, and 

 of the anterior half of the articulation between dorsal 2 and dorsal 3. The 

 articular facets are seen to be single pairs and to consist of an oval surface 

 {m.z.p., m.s.a.) placed entirelj^ on the neural arch. The left anterior articular 

 facet of dorsal 2 (middle figure) shows a tendency to divide into two. 



Letters as in text-fig. 64, with the addition of cos., process for the articulation of the 

 tubercle of the first rib ; c.p., concave facet for the head of the second rib ; 

 X., hypapophysial tubercle. 



In Giraffe, as a marked exception, it is small in all the cervicals 

 and smaller in cerv. 6 than in the cervicals in front of that one, 

 indeed so much reduced that it has no posterior extension at all 

 but is represented by a small tiiangular anterior growth only. 



