Chap. IX.] 



SKELETON OF FISHES. 



3 2 3 



inferior to the notochord, or the modified urostyle 

 which has taken its place. 



The unpaired dorsal fins of Fishes are connected 

 with the vertebral column by means of spines, which 

 are placed be- 

 tween the neu- 

 ral spines of the 

 vertebrae, and 

 are connected 

 with the dermal 

 spines or fin 

 rays which sup- 

 port and make 

 up the greater 

 part of the fins 

 themselves. 



In many 

 fishes there is 

 very constantly 

 developed a 

 h?emal aswell as 

 a neural arch of 

 bone in connec- 

 tion with the cen- 

 trum, and these, 

 like the superior, 

 are produced 

 into a spine ; 

 in the hinder re- 

 gion of the body 

 interspinous 

 bones are de- 

 veloped between 

 these so-called hsemaphyphyses, and they serve to 

 carry the fin rays of the anal fin. 



Articulated to the atlas is the skull, which, in the 

 first place, is the box or covering for the brain ; this 



