THE TRUE FISHES. 



FlG. 202. Devil-fish (Cephalopterus diabolus). 



Order II. Holocephali. The Chim&ra (Fig. 203) is 

 a northern representative of this group, while the curious 

 Caliorhynchus is found in Antarctic regions. The gill- 

 openings are protected by a membranous covering, sug- 

 gesting the gill-covers of bony fishes. The teeth are curi- 

 ously arranged, there being four in the upper and only two 



FlG. 203. The Chimcera. 



in the lower jaw. The air-bladder is absent. The male 

 Chimsera has a curious, comb-like, cartilaginous appendage 

 armed with hooklets on the top of the head, that is either 

 erect or hidden in a hook-armed groove. 



