SKELETON. 



553 



(c} Along the floor : basi-occipital, paraspjkenoid, . 



(d) Around the ear on each side : sphenotic, pterotic, and epiotic 



(above), prootic and opisthotic (beneath). 



(e) In front of and around the orbit : parethmoid, lachrymal) 



orbitals. 



Thus the haddock's skull shows in two respects an ad- 



,s.o. 



FIG. 295. Disarticulated skull of cod. 



S.O., Supra-occipital; Pa., parietal;^., frontal; M.E., meseth- 

 moid ; N., nasal ; P.E., parethmoid ; Of., otics ; E.O., ex-occi- 

 pital; B.O., basi-occipital; Pa.S., parasphenoid ; V., vomer; 

 Z.., lachrymal; orb., orbitals; H.M., hyomandibular ; S. t 

 symplectic ; Q., quadrate; Pt., pterygoid ; mt.pt., metaptery 

 goid ; -ms.pt., mesopterygoid ; PL, palatine; MX., maxilla; 

 Piny., premaxilla ; A r. , articular ; An., angular; D., dentary; 

 u.k., urohyal ; h.h., hypohyal ; c.h., ceratohyal ; ep.h., epihyal ; 

 i.h., interhyal ; Op., opercular ; S.op. t sub-opercular ; i.op. t 

 inter-opercular ; p. op., prae- opercular. 



vance upon that of the skate : first, in the ossification of the 

 primitive cartilage ; and second, in the addition of membrane 

 bones. Of the latter, the parietals and frontals cover over 

 the spaces which in the skate form the fontanelles. 



