168 



THE ANATOMY OP VEETEBEATED ANIMALS. 



ginoiis vertebral centi-a. Tlie pTOximal ends of ossified 

 neural arches, of ribs, and, in the candal region, of inferior 

 arches, are imbedded in the sheath of the notochord. 



Fig. 51. 



Fig. 51.— The Mudfish {Lepidosiren). 

 Fig. 52. 



Mn 



Fig. 52. — Skull oi Lepidosiren annectens : — A, the parieto-frorital bone ; 

 B. the supra-orbital ; C, the nasal ; D, the palato-pterygoid ; E, 

 the vomerine teeth ; ^. O., the ex-occipital ; JI/h, the mandible ; Hy, 

 the hyoid ; Br, the branchiostegal rays; Op, the opercular plate ; x, 

 the parasphenoid ; y, the pharyngo-liranchial ; Or, the orbit ; Au, 

 the auditory chamber ; N, tlie nasal sac. 



Fin-rays support the median fin. The skidl, the palato- 

 quadrate, and suspensoi'ial apparatus, foi-m, as in Chimcera, 



