376 



THE DOGFISH 



LESS. 



The vertebral column has the general charactei of a 

 jointed tube surrounding the spinal portion of the neural 

 canal. Lying beneath this cavity, i.e., between it and the 

 ccelome, is a longitudinal row of biconcave discs, the ver- 



tr.jbr 



FIG. 101. A, Three trunk vertebrae of Scyllium from the side. 

 B, a single trunk vertebra viewed from one end. 

 c, three caudal vertebrae from the side. 

 D, a single caudal vertebra from one end. 



f, centrum ; //. a, haemal arch ; n. #, neural arch ; tr. pr. transverse 

 process. 



(After Hasse.) 



tebral centra (Fig. 101, c ; Fig. 99, V. Cent) : they are 

 formed of cartilage, but have their anterior and posterior 

 faces strongly calcified. The biconcave intervals between 

 them (Fig. 99, A) are filled with a gelatinous matter or inter- 



