1865.] AXIAL SKELETON IN THE PRIMATES. 585 
family ; all the dorsal spines backwardly inclined or vertical * ; mostly 
four, sometimes five, lumbar vertebree ; dorsal and lumbar vertebre, 
taken together, only eighteen, or even only seventeen, in number; 
lumbar neural spines scarcely inclined forwards ; transverse processes 
of lumbar vertebrze not bent downwards, and arising from a higher 
level than in other Cebid@ ; transverse diameter of thorax exceeds 
its depth ; sacrum generally composed of four vertebre, three often 
articulating with the ilium ; sacral region longer in proportion to the 
rest of the spine than in any other of the Cedide, or any of the St- 
miide below Hylobates ; number of caudal vertebree at its maximum 
in the order; proportion of caudal region to other vertebral regions 
at its maximum ; longest individual caudal vertebre situated further 
from the root of the tail than in other long-tailed forms; eight cau- 
dals with a complete neural arch to each; five or six caudals with a 
neural spine each; caudal zygapophyses articulate with each other 
till the eighth caudal vertebra; caudal metapophyses distinct to the 
same vertebra; anterior and posterior divisions of the caudal trans- 
verse processes not attaining equality till the ninth caudal vertebra ; 
transverse processes of the first six caudal vertebrae very long and 
strong; hypapophyses and chevron bones at their maximum, and 
in the posterior caudal vertebree they are the largest of the caudal 
processes ; terminal caudal vertebrz thick. 
This genus also differs from all the rest of the Cebid@ and from 
all Semnopithecine and Cynopithecine in the small increase in 
antero-posterior extent of the lumbar neurapophyses and spines as 
compared to those of the dorsal region, and in the shortness of the 
lumbar anapophyses. 
Fig. 11. 
Last dorsal and three first lumbar vertebre of Lagothrix humboldtii, from the 
Museum of the Royal College of Surgeons. Nat. size. 4. Hyperapophysis. 
* De Blainville remarks this (/. c. p. 10); but in the skeleton (no. 38 4) in the 
British Museum the thirteenth and fourteenth dorsal spines are turned slightly 
forwards. 
+ As in two skeletons in the Museum of the Royal College of Surgeons (nos. 
4690 & 4697). 
Proc. Zoo. Soc.—1865, No. XX XVIII. 
