354 



TELEOSTEI 



ac 



Flfi. 338. 



Transverse section of the vertebral column in the trunk of a very young Trout (S///ir>). 

 enlarged. .&, dorsal wall of air-bladder; a.c, abdominal coelom ; Id, basidorsal cartitajfe ; 

 bv, basiventral cartilage; c, posterior cardinal vein; el, elastica externa ; /., librous sheath 

 suiroimding notochord ; g.r, genital ridge ; li, dorsal longitudinal ligament ; m.d, mesonephi ie 

 duct ; n.c, nerve-chord.; r, rib ; si, skeletogenous tissue. 



A. 



B. 



na 



Flu. 381>. 



Caudal vertebrae of Thynnus vulqaris (Guv. and Val.). A, right-side view ; B, left-side 

 view of the same cut in half, a.v, anterior ventral process ; a.z, anterior ' zygapophysis ' ; o, 

 centrum ; h.a, haemal arch ; n.a, neural arch ; p.v, posterior ventral process ; p.z, posterior 

 ' zygapophysis ' ; r place of attachment of rib. 



