327 



by the long vomero-ethmoid and at its base by the much 

 shorter maxillaries; lower jaws equally produced, slender and 

 recurved ! ). Cleft of mouth reaching behind eye. Eyes moderate. 

 Nostrils close together near frontborder of eye. Tongue not 

 free. Vomer and jaws with close set teeth, the point of which 

 may be directed backward. Gillopenings wide, separated by 

 a small interspace, where the gillmembranes are united to the 

 isthmus. Branchial openings in pharynx are wide slits. 



Distribution: Bathypelagic fishes of the warm and 

 temperate seas. 



Key to the i nd o-australian genera of 

 Nemichthyidae. 



1. Anus immediately behind pectorals. Origin of dorsal before 

 that of pectorals. Jaws equal in length. 



a. L. 1. without pores Cercomilus p. 327. 



b. L. 1. with 3 series of pores Nemichthys p. 328. 



2. Anus far distant from pectorals. Origin of dorsal behind 

 that of pectorals. Jaws unequal in length. 



a. Origin of dorsal behind that of anal Serrivomer p. 331. 



b. Origin of dorsal immediately behind base of pectorals. Avocettina p. 333. 



i. Cercomitus M. Weber. 

 (MAX WEBER, Siboga-Exp. Fische 1913, p. 54). 



Very slender and elongate, compressed, tapering from the 

 middle of the length to pectorals and strongly to the end of 

 the tail, which is transformed into a very thin flagellum. Anus 

 at a short distance from base of pectorals. Origin of dorsal 

 at some distance before that of pectorals. Anal originating 

 immediately behind anus, its membrane reaching the point of the 

 flagellum. Headbones very thin and transparent. Head of 

 moderate size, tapering into the long, exceedingly narrow jaws, 

 which are of equal size, strongly diverging ') and somewhat 

 swollen at their end; the upper jaw strongly curved upwards. 

 Nostrils close together, somewhat before eye, rounded. Eyes 

 situated high, their upper border in the dorsal profile. Jaws and 

 vomer closely set with small teeth, the point of which is 

 directed backwards. No scales. Lateral line without pores. 

 Gillopenings narrow, situated before and below pectorals. 



i) See note on page 326. 



