HIGH SCHOOL ZOOLOGY. 



83 



may be represented by a small stapes or columella which fills 

 up a gup or window (the fenestra ovalis) in the outer wall of 

 the auditory capsule, present in all Vertebrates except fishes. 

 A pteiygopalatine rod and premaxillse are pi*esent on each side, 

 but the maxilla is even more rudimentary than in the catfish. 

 There is no gill-cover nor branchiostegal rays, but the visceral 

 skeleton is well represented, although the hinder arches are 

 reduced in comparison with the catfish. (Fig. 61). 



h 



Fig. 61. — Visceral Skeleton of Menobranch. 

 (After Huxley). 



h. hyijohyal ; ch. ceratohyal ; bb. first, bb^. second basibranchial ; cb', cb=, first 

 and second ceratobranchials ; eb», eb^, eb'', 1st, 2nd and 3rd epibranchials ; gl. glottis. 



5. Great difficulty will be met with however, in com- 

 paring the limbs and the girdles which support them witli tho 

 corresponding parts in the catfish (Fig. 62). There the cora- 

 coids are bony and articulate in the middle line ; here they are 

 cartilaginous and overlap the middle line ; they furthermcre 

 each give off a process jutting forward, the precoracoid, some- 



