SKELETON OF QUADRUMANA. 521 



of the transverse process are united, external to the perforation by 

 the vertebral artery. In the fourth cervical the pleurapophysial 

 part projects distinctly below the diapophysial part, and progres- 

 sively diverges in the fifth and sixth, increasing in size, especially 

 in the latter, without, however, acquiring that antero-posterior 

 breadth which gives it the lamelliform character in the inferior 

 apes. The transverse process of the seventh cervical consists 

 of the diapophysis only, and is grooved below, not perforated, by 

 the vertebral artery. The distinct nature of the equally simple 

 transverse process in the second and seventh cervical vertebras of 

 this Orang is well shown by their different relative positions to 

 the groove with which the vertebral artery has impressed them. 

 The neural spine of the axis is bifurcate ; that of the third 

 cervical is simple, long, and slender ; those of the succeeding 

 cervicals are still longer, and progressively increase in thickness 

 as well as length. The metapophysis appears as a tubercle near 

 the base of the anterior zygapophysis of the twelfth dorsal : it is 

 equally distinct on the first lumbar, but subsides to a slight emi- 

 nence on the succeeding lumbar vertebrae. The anapophysis is 

 only distinguishable from the diapophysis upon the first lumbar 

 vertebra ; it is not so developed as to interlock, but serves to illus- 

 trate the relation of the diapophysis of that vertebra to those of 

 the antecedent dorsals and the succeeding lumbars. The spine of 

 the third dorsal has an anterior and posterior prominence: the 

 succeeding spines gradually diminish in length, but increase in 

 breadth and antero-posterior extent to the penultimate lumbar. 

 Seven pairs of ribs directly articulate with the broad sternum, 

 which consists of the manubrium and four pairs of ossicles, the two 

 lower pairs of which have coalesced. The manubrium is relatively 

 shorter than in the Gibbons, and receives only the first and part 

 of the second pairs of ribs. As a rule, the number of dorso- 

 lumbar vertebrae, in Pithecus, is 16: that of the sacro-caudal 

 vertebra 8. The first rib is less curved, and describes a smaller 

 portion of a circle than in Man : its head is relatively larger, and 

 is supported on a shorter neck : it has an epiphysis, as in Man. 

 The distal portion is relatively less expanded than in Man. The 

 other ribs chiefly differ in their more compressed form and their 

 more gradual and equable curvature. 



In the Chimpanzee (^Troglodytes iiiger, fig. 345), the vertebral 

 formula is: — 7 cervical, 13 dorsal, 3 or 4 lumbar, 5 or 6 sacral, 

 and 2 or 3 caudaL The pleurapophysial portion of the transverse 

 process of the atlas is shorter than in the Orang, and has not 

 united with the longer diapophysial division : the canal for the 



