1865.] AXIAL SKELETON IN THE PRIMATES. 591 
lumbar anapophyses very faintly marked ; metapophyses more di- 
stinct in the three first caudals than in all the rest of the spine; no 
hyperapophyses. 
CHEIROMYIDE. 
Atlas with two distinct articular surfaces for axis ; spines of third, 
fourth, fifth, sixth, and seventh cervical vertebree almost obsolete ; 
thirteenth dorsal spine turned forwards ; a process like a second ana- 
pophysis in some lumbar vertebrae; transverse process of fourth 
cervical vertebra bifurcating; nine pairs of true ribs; two sacral 
vertebree ; no hyperapophyses ; no distinct metapophyses or anapo- 
physes in the cervical region. 
To sum up the results of these observations, the Primates present 
us (as regards their vertebral column only) with four principal types 
of structure, well represented, respectively, by (1) Simia, (2) Cerco- 
pithecus, (3) Nycticebus, and (4) Lemur,—the first having, however, 
many points in common with the third, and the second with the 
fourth ; so that the affinities between the various groups of the 
order (as regards their spinal characters) may be represented under 
the symbol of atree. The trunk of such a tree (fig. 13) divides into 
two main branches—one of them representing the forms possessing 
few caudal vertebree, an elongated tapering sacrum, inconspicuous 
metapophyses or anapophyses, neural spines of trunk nearly always 
vertical or backwardly inclined, and that of the axis more or less 
bifid or trifid, cervical vertebrae short, and cervical spines sometimes 
very produced—that is to say, the forms included in the family 
Hominide and in the subfamilies Simiine and Nycticebine ; the 
other main branch representing all the rest of the order, and possess- 
ing the characters attributed above to the Simiide (other than the 
Simiine), the Cebide, the Hapalide, and the Lemuroidea in common. 
The first main branch gives off a secondary one to represent the 
Nycticebine, and then divides into three others for (1) Homo, (2) 
for Troglodytes and Simia, and (3) for Hylobates. The second main 
branch bifurcates,—its first division representing the Simiide other 
than the Simiine, together with the Cebide and Hapalide ; its 
second denoting the Lemuroidea other than the Nycticebine. From 
both the Semnopithecine and Cynopithecine Inuus and Cynocephalus 
distinguish themselves as separate twigs; and Afeles diverges from 
the Cebide generally, and very interestingly parallels Hylobates in 
its long cervical neural laminz, backwards inclined neural spines of 
trunk-vertebrze, large transverse diameter of thorax, and slightly 
marked metapophyses and anapophyses. Mycetes and Lagothrix 
also, with their marked hyperapophyses, and Chrysothriz, with its 
undivided caudal transverse processes, are also special forms. The 
genera Galago, Tarsius, and Cheiromys, with their rudimental cer- 
vical spines, diverge so much from the typical Lemurs that they 
might almost be represented as a distinct primary division of the 
second main branch, instead of a subdivision of that bifurcation which 
culminates in Lemur, and which gives off a twig to represent Indris 
