254 
TEirriAllY YERTEEEATA OF THE EAYtjAf. 
are separated ventrally hy an interval of about 2 cm. 'J'lie neural arcli is a comparatively 
narrow bar of bone connected antero-externally with the u})])er border of the condylar 
promimmees by a thin bar of bone as described above ; on the frotit of the bar there is 
a low nu'dian rid<>o (vo.syu), but on the hinder face there is a flat ficet, against wdiich 
the antc'ro-ventral snrface of the arch of the axis tits (see text-fig. 83, D). The 
transverse process is short and massive and directed a little backw'aids; on the 
])osterior lace, immediately outside the edge of the surface for the axis, there is a small 
foramen, wdiich, how ever, does not seem to perforate the transverse process, but merely 
leads into the bone. The surfaces for the axis are wide above, narrowing ventrally, 
and passing into the surface for the odontoid without interruption ; they are slightly 
convex from side to side. The ventral bar bearing the odontoid facet is stout and 
is produced dowinvards into a shar[)-hooked hypapophysis [hjjp-] ; from Lucas’s 
description* it seems that a similar process is present in the atlas oi Zeuglodon cetoides. 
In the aids (text-fig. 83, B, ])) the odontoid process {od.) is short, blunt, and 
rounded, passing at least ventrally into the lateral surfaces {at.) for the atlas. These 
axe (piadrate in outline, and nearly flat or even very slightly concave from side to side. 
The neural arch is high, and the neural spine (??.«/;.) high and massive ; it is triangular 
in section, the posterior surface being flat, wdiile the two anterior faces meet in an 
acute angle, the lower end of which overhangs the odontoid process ; or the ventral 
face of this projecting jiortion of the arch is a flat facet wliich articnlates with the corre- 
sponding surface on the posterior side of the neural arch of the atlas (text-fig. 83, D). 
The posterior zygapophyses {p.z.) are well developed. The transverse })rocess {t.p.) is 
a flange of bone directed a little backwards, and extending from the base of the neural 
arch to the ventral border of the centrum ; externally it is divided into an upper and 
lower process, and its base is ])erforated obli(Hiely by a vertebrarterial canal [v.c.). 
The posterior face of the centrum is much broader than high ; it is slightly concave, 
and in this specimen the epiphysis is not completely fused wdth the rest of the centrum. 
'Fbe ventral lace cf the centrum is imperfect. The third cervical (text-tig. 83, C, D) 
is remarkable for the extreme shortness of the centrum, which in the middle is only 
about 1'5 cm. through, while its width is at least 5 cm. The centrum is oval in 
outline, and is completed by anterior and posterior epiphyses {ep.), here still separated ; 
the anterior and ])osterior faces are slightly concave, 'i'lie neural arch is high, and 
rises into a short stout neural s])ine {n.sp.) directed a little backwards. Both the 
anterior {a.z.) and ])osterior zygapophyses {p.z.) are well developed and nearly circular 
in outline, d'ho transverse ])rocess {t.p.) is wide, and consists of a narrower upper bar 
arising from the base of the arch and a much broader ventral bar from the lower half 
of the centrum; these unite externally, enclosing a large vertebrarterial canal {v.c.), 
:ind forming a broad ])latc, the outer angle of which is produced ii little downwards. 
Aiiu'r. Naliiralisf, vol. (ISO-')) p. TKi. 
