70 



the first caudal vertebra*, but coalesce and develope a spinous process from 

 their distal anchylosed extremities in the succeeding ones. The inferior spine 

 increases in length in the third and fourth vertebra, and then progressively di- 

 minishes to the fifteenth ; it disappears in the sixteenth, and all trace of hsem- 

 apophyses is lost in the seventeenth caudal vertebra. 



The bodies of the anterior caudal vertebree, in so far as they can be viewed 

 apart from their large and numerous processes, are sub-cubicalf, but slightly 

 expand to form transversely-elliptical articular extremities. The transverse pro- 

 cesses arise, in the anterior vertebrae, from the base of the neurapophysis and 

 upper part of the side of the centrum, but descend in the rest to the middle of 

 the side of the centrum. The long transverse processes of the anterior vertebrae 

 are directed outwards, and a little backwards : they are depressed, flattened, and 

 without tubercle or ridge below, convex above, and with a well-marked tubercle 

 on this aspect: it is situated near the end of the process in the first caudal|, 

 but nearer the base in the second, third and fourth vertebrae ; in the fifth it 

 assumes the form of a ridge, and a second tubercle is developed near the end of 

 the process, which also assumes the form of a ridge on the upper part of the 

 transverse processes of the eighth to the fourteenth caudal vertebrae inclusive. 

 The anterior margin of the transverse process forms a slight angle at its middle 

 part in the sixth caudal ; this angle is progressively extended forwards, and, by 

 the shortening of the transverse process, external to and behind it, it comes to 

 be situated at the anterior angle of the end of the process, which thus appears 

 bifurcated in the tenth caudal vertebra. In the thirteenth the anterior produc- 

 tion of the end of the transverse process is the longest, and in the seventeenth 

 and following vertebrae it is the sole representative of that process. The ex- 

 tremities of the transverse processes in the fourth, fifth and sixth caudal verte- 

 brae are the thickest. The neural arch rises from the anterior two-thirds of the 

 body of the vertebra, and quickly expands into the large anterior and small pos- 

 terior articular processes. The articular surfaces of the anterior processes in 

 the first caudal are concave and look inwards §, embracing or clasping the pos- 

 terior convex-articular processes of the last sacral vertebra. The articulations 

 of the anterior obUque processes in the remaining caudal vertebrae are less con- 



* PI. VIII. fig. 5. b, b. t Fig. 8. I Fig. 5. § Figs. 6 and 7. d. 



