NOTACANTHIDif:. 523 



coasts, but tliey are veiy scarce, not more than sixteen cap- 

 tures having been recorded between the years 1759 and 

 1878. 



Nineteenth Division — Acanthopteeygii Notacanthi- 



FOEMES. 



Dorsal fin short, com/poscd of short, isolated spines, toitliout 

 a soft portio7i. Anal fin very long, anteriorly with many 

 spines ; ventrals abdominal, with more than five soft and several 

 unarticulated rays. 



Notacanthus is the most aberrant type of Acanthoptery- 

 gians. Of the characteristics of this order the development 

 of spines in the vertical tins is the only one preserved in the 

 fishes of this genus. Their body is elongate, covered with 

 very small scales; the snout protrudes beyond the mouth. 

 Eyes lateral, of moderate size ; dentition feeble. Five species 

 are known from the Arctic Ocean, Mediterranean, Atlantic, 

 and Southern Pacific. They inhabit considerable depths, 

 probably from 100 to 400 fathoms, and during the " Chal- 

 lenger" expedition specimens have been obtained from an 

 alleged depth of 1875 fathoms. 



SECOND OEDER: 

 ACANTHOPTEEYGII PHARYNGOGNATHI. 



Part of the rays of the dorsal, anal, and ventral fins are 

 non-artieidated spines. The loiver pharyngeals eoaleseed. Air- 

 bladder without p^nemnatic duct. 



Fig. 239. — Coalescent Pharyngeals of Scarus cretensis. 

 a, upper ; h, lower pliarjiigeals. 



