184 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 9 



3b. Upturned labial flange narrow. 



4a. Inferior edge of labial canal straight, not developed into a 

 broad shield or winglike plate ; dorsal origin before pectoral 

 base ; tail much longer than head and trunk .... 



. Alloconger Jordan and Hubbs 



4b. Inferior edge of labial canal expanded into a broad shield or 



winglike plate, reaching to oral edge of lip; dorsal origin 



over pectoral base; tail barely longer than head and trunk 



Thyreoconger, new genus 

 lb. Edge of upper lip without a free, upturned, labial flange; bony 

 projections from inferior edge of labial canal present. 



5a. Vomerine teeth in a band, not extending backward on the 



shaft of the vomer in a single row; labial canal sending 



two or three short processes downward to the edge of the 



moderately extensible upper lip. 



6a. Maxillary, premaxillary, and vomerine teeth closely 



united into a single patch at the tip of the upper jaw. 



7a. Teeth very short, almost pavementlike in appearance ; 



vomerine band widened posteriorly, covering much 



of the roof of the forepart of the mouth ; tip of snout 



swollen; premaxillary teeth almost entirely inside of 



mouth when closed . . . Promyllantor Alcock 



7b. Teeth longer never pavementlike; vomerine band 



narrowed posteriorly; premaxillary teeth largely 



exposed when mouth is closed 



Rhynchocymba Jordan and Hubbs 

 6b. Premaxillary and vomerine teeth separated by a distinct 

 interspace. 



8a. Snout considerably projecting; all premaxillary 

 teeth visible from directly below with mouth 

 tightly closed; dentition normal, teeth not greatly 



enlarged; color not blackish 



Congrina Jordan and Hubbs 



8b. Snout scarcely longer than lower jaw; nearly all of 

 premaxillaiy teeth hidden when viewed from 

 directly below with mouth tightly closed ; denti- 

 tion very strong; premaxillary teeth, anterior 

 vomerine teeth, and front teeth of lower jaw 

 greatly enlarged canines; blackish eels of deep 

 water .... Bathyuroconger Fowler 



