1865.]} AXIAL SKELETON IN THE PRIMATES. 589 
but the lowest part of each cervical centrum is remarkably prolonged 
in a backward direction as a hypapophysial ridge *, 
Lemur. 
This genus agrees with the last in the very elongated cervical ver- 
tebree and the little relative extent of the dorsal region, also in the 
cervical neural laminz exceeding those of the dorsal vertebree in 
antero-posterior extent, in the atlas having but one posterior articular 
surface for the axis, and in the large size of the transverse process of 
the atlas. The spine of the axis, however, has its upper part pro- 
duced in a backward as well as in a forward direction ; there are 
many caudal vertebrx, and there are caudal hypapophyses and che- 
vron bones; the spines of the lumbar vertebrze are very long, and 
produced strongly forwards. Often the transverse processes of both 
the fourth and fifth cervical vertebrze are bifurcated; sometimes there 
are extra short transverse processes to the lumbar vertebree, and the 
normal ones are produced strongly downwards and forwards. 
Microcesvus. 
According to Dr. Peters+, there are seven lumbar vertebre in this 
genus. 
NYCTICEBINE, 
This family contains forms, the vertebral structure of which is 
aberrant, and singularly recalls in some of its details the family Ho- 
minide and the subfamily Simiine. 
Atlas with less extended transverse processes than in the other 
Lemuride, and sometimes with two articular surfaces for junction with 
the axis ; spine of axis bifid or trifid ; transverse process of the third 
cervical vertebra often, those of the fourth and fifth cervicals always, 
bifurcated ; cervical vertebree very short, and therefore quite unlike 
those of Lemur and Indris; dorsal and lumbar spines all backwards 
inclined, or sometimes the latter only very slightly forwards ; increase 
in length and breadth of dorsal vertebree backwards very slight ; 
metapophyses mostly inconspicuous}, but sometimes developed in 
the cervical region ; anapophyses but little developed ; sacrum long 
and tapering posteriorly ; caudal vertebrae few, no caudal hypapo- 
physes ; increase in breadth of the lumbar vertebral bodies as com- 
pared with the dorsal at its minimum ; neurapophyses sometimes di- 
rectly perforated by the spinal nerves; ribs from fourteen to sixteen 
pairs; dorsal region much relatively extended, cervical region very 
little so. 
Nycricrsus. 
Spine of third cervical vertebra generally bifurcated ; dorsal ver- 
* This, as well as many of the above characters, is noticed by Prof. Owen in 
his remarks on the skeleton of this species (see Osteological Catalogue, vol. ii. 
p. 717). He also notices that the Paris specimen has an extra pair of ribs, 
t Reise nach Mossambique, p. 17. 
t Le. not projecting strongly upwards as in the Long-tailed Monkeys and 
murs. 
