The Skeleton of the Fish 



47 



Each vertebra consists of a double concave body or centrum 

 (66). Above it are two small projections often turned back- 

 ward, zygapophyses (71), and two larger ones, nenrapophyses 

 (67), which join above to form the neural spine (68) and thus 

 form the neural canal, through which passes the spinal cord 

 from end to end of the body. 



Below in the vertebrae of the posterior half of the body the 

 hcemapophyses (69) unite to form the Jiccnial spine' (70), and 



Fig. 29. — Pharyngeal bone and teeth of European Chub, Leuciscus cephalut 

 (Linnceus). (After Seelye.) 



Fig. 30. Fig. 31. 



Fig. 30. -Upper pharyngeals of a Parrot-fish, Scam, strongulocephalus .. • • •- 

 Fig. 31.-Lower pharyngeals of a Parrot-fish, Scar«.s strong yloccphalus (Blpeker). 

 tnrough the hcemal canal thus formed passes a great artejy. The 

 vertebrae having hsemal as well as neural spmes are known as 

 caudal vertebrcB, and occupy the posterior part of tl|e body, 

 usually that behind the attachment of the anal fin (j^. 



The anterior vertebra; known as abdominal vertebra, bound- 

 ing the body-cavity, possess neural spines similar to those of 



