TIIK VKHTKLiKAL rOLUMX. 



17 



the eighth, presents an articular head covered with cartilage ; the 

 anterior surfaces, with the exception of the ninth, present corre- 

 sponding articular depressions, covered with cartilage. 



b. The orclii 3 *, which have some- 

 what sharp margins both before and 

 behind, bear the following pro- 



- : 



1. The articular processes (Figs. 

 4 and 5 o o] are similarly placed 

 to. those of the dorsal vertebrae of 

 man : they project horizontally, the 

 cartilaginous articular surfaces on 

 the posterior processes being directed 

 downwards, those on the anterior 

 upwards. 



2. The transverse processes 

 (Figs. 4 and 5 / f') are strong, flat. 

 and of very varying size and direction. 

 The transverse processes of the fourth 

 vertebra are the longest, those of the 

 third only a little shorter; the shortest 

 are those of the seventh and eighth. 

 The atlas has no transverse pro- 

 cesses. Those of the second and third 

 vertebrae project directly outwards 

 and slightly downwards ; those of 

 the fourth, fifth, and sixth upwards 

 and backwards. The seventh and 

 eighth project more directly outwards 

 and at the same time backwards ; 

 the ninth upwards and markedly 

 backwards. All the transverse pro- 

 cesses have cartilaginous epiplr 



the largest are those of the second, 

 third, fourth, and ninth vertebrae. 



3. The spinous processes are 

 generally small, but individually of 

 varying size, appearance, and direc- 

 tion. The longest are those of the third, fourth, and fifth vertebrae ; 

 these are, in transverse section, of a three-sided prismatic form,, as 



c 



Vertebrae of Rttna acultnta, seen from 



below, twice the natural size. 

 i to 9 First to ninth vertebrae, 

 c Urostyle. 

 c o Articular processes. 

 *c The two facets for articulation with the 

 urostvle. 



