notacanthidjE. 623 



coasts, but they are very scarce, not more than sixteen cap- 

 tures having been recorded between the years 1759 and 

 1878. 



ISTlNETEENTH DIVISION — ^ACANTHOPTEEYGII NOTACANTHI- 

 FOEMES. 



Dorsal fin short, composed of short, isolated spines, without 

 a soft portion. Anal fin very long, anteriorly ivith many 

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

 mnarticulated rays. 



Notacanthus is the most aberrant type of Acanthoptery- 

 gians. Of the characteristics of this order the development 

 of spines in the vertical fins 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: 

 ACANTHOPTERYGII PHARYNGOGNATHI. 



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

 non-articulated spines. The lower pharyngeals coalesced. Air- 

 hladder without pneumatic duct. 



Fig. 239. — Coalescent Pharyngeals of Scanis cretensts. 

 a, upper ; d, lower pharyngeals. 



