FISHES. 



51 



remains of the notochord) ; on each side, the exocdpital (10) ; and 

 the mpraoccipital ttbove (8), which is raised into a crest. The 

 formation of the posterior part of the skull is completed by the 

 mastoids (12) and parietak (7). 



On the lower surface of the skull (fig. 38) are seen the basi- 



Fiff. 38. 



Lower view of skull of Perch. 



sphenoid (6), the vomer (16), which, like the palatines, is beset 

 with teeth, the alisphenoids (11), and orbitosphenoids (14). 



In addition to these bones we have to notice those of the 

 upper surface of the skull (fig. 37), viz. the Jrontals (1), the 

 prefrontals (2), the postjrontals (4), and the turbinak (20), all 

 paired bones. 



Attached to the skull are the hyo-branchial apparatus and the 

 scapular arch (figs. 39, 40). 



