﻿241 



1. Body scaly. Anterior nostrils on top of snout, poste- 

 rior in front of eye. Tongue free. Pectorals present. 

 Dorsal, anal and caudal well developed. Origin of 

 dorsal far behind gillopenings. Branchial openings 



in pharynx wide slits A/ii^uUlu/ac' p. 242. 



2. Body scaleless. End of tail not free but with the 

 caudal confluent with dorsal and anal, which both 

 may be rudimentary. 



a. Nostrils lateral or superior. 



1. Pectorals present. Dorsal, anal and caudal 

 well developed. Anus in anterior half of length. 

 Tongue free or not. Teeth in narrow bands 

 or at least partly in 2 or more series. 



Branchial openings in pharynx wide slits. Congridae p. 251. 



2. Pectorals present. Dorsal, anal and caudal 

 well developed. Anus in anterior half of length. 

 Tongue not free. Teeth acute, uniserial. Bran- 

 chial openings in pharynx narrow slits . . . Nccnclu-lidae p. 268. 



3. Pectorals absent. Dorsal, anal and caudal well 

 developed. Tail ending in a slender tip or 

 filament. Anus in anterior half of length. 

 Tongue not free. Teeth cardiform bands. 

 Branchial openings in pharynx wide slits. 



Bathypelagic Nettastomidae p. 269. 



4. Pectorals absent. Dorsal, anal and caudal 

 well developed. Anus in anterior half of 



length. Tongue free. Acicular teeth in bands. Heterocongridac ^. 2'}\. 



5. Pectorals absent. Dorsal, anal and caudal 

 more or less developed, covered by thick skin ; 

 if dorsal and anal are rudimentary or absent, 

 the teeth are bi- or triserial. Anus before or 

 behind middle of length. Tongue not free. 

 Teeth in one or more series. Branchial 



openings in pharynx narrow slits Miiracnidac p. 343. 



6. Pectorals small, vestigial or absent. Dorsal 

 and anal confined to the tail; they may lie 

 reduced to a low fold. Anus far behind middle 

 of length. Tongue not free. Teeth uniserial. 

 First branchial opening in pharynx wide, fol- 

 lowing narrow slits Moruiguidac p. 336. 



b. Posterior nostrils generally near eye in the upper 

 lip in a valve or protruding flap ; anterior nostrils 

 in a short tube at the margin of the upper lip. 



InUO-AUSTKAI.IAN I'lSUES III. 16 



