170 Transactions. — Zoology. 



hyperapophyses ; the articular face looks inwards and slightly 

 ventrad. In the axis the pre-axial articulating surface is 

 crescentic, the height not quite half the breadth, and nearly 

 straight dorsad, at the root of the odontoid process. The post- 

 axial surface is higher than broad, with straight sides, and 

 both dorsal and ventral margins concave. The odontoid pro- 

 cess is moderate, tapering, bluntly rounded, the upper surface 

 concave ; a slight cup on each side, near the base, for articula- 

 tion with slight tubercles at the post-axial bases of the neural 

 laminae of the atlas. The hypapophysis is strongly developed 

 post-axially, but fades away about the middle of the centrum, 

 the anterior portion of which is smooth. Neural platform 

 triangular, its post-axial margin slightly concave, and its 

 breadth considerably greater than the length to the tip of the 

 odontoid. Neural spine short and stout. The post-zygapo- 

 physes look almost completely ventrad, but slightly post- 

 axiad ; the hyperapophyses prominent and rounded, not com- 

 pressed. Anterior cervicals, 3 to 6 : The post-axial margin of 

 neural platform straight in No. 4, concave in Nos. 5 and 6. 

 Neural spine divided to the base in all. Hyperapophyses 

 strong on Nos. 3 and 4 only. Middle cervicals, 7 to 14 : Centra 

 moderate or rather short; the post-axial face narrowed 

 dorsad : breadth at ventral margin less than one and a half 

 times that of the dorsal margin ; the height slightly greater 

 than the dorsal breadth. Generally a pneumatic foramen 

 below the diapophysis in Nos. 10 to 14 ; sometimes another 

 behind it in Nos. 12 to 14. The hypapophyses from Nos. 

 9 to 14 rise some distance behind the pre-axial border of 

 the centrum. The neural ridges rise abruptly, and from 

 Nos. 6 to 12 they converge rapidly, the distance apart of 

 the post-axial ends being considerably more than twice 

 that of the pre-axial ; but in Nos. 13 and 14 they are more 

 nearly parallel. The transverse bar is very low, and rises 

 obliquely. There is a deep conical pit on each side at the 

 pre-axial ends of the neural ridges, usually with a foramen at 

 the bottom ; there is also usually a foramen in the inner 

 faces of the neural ridges, near their anterior ends. The 

 faces of the post-zygapophyses look more outwards than in 

 Mcionornis. Posterior cervicals, 15 to 21 : The centra are 

 short; the post-axial face in No. 19 has the height in the 

 centre about equal to the dorsal breadth. There is a pneu- 

 matic foramen behind the diapophysis in all, and usually one 

 below it also. The hypapophyses are separated from the 

 anterior border of the centrum by a transverse groove. They 

 are single on Nos. 19 to 21, usually forked on No. 18, and 

 double on No. 17. The neural spine is single on No. 20 ; 

 double, or forked, on No. 19. Hyperapophyses are well 

 marked on 18 to 21. 



