212 
vertical or nearly so. Small teeth in jaws, present or absent on vomer* No 
barbel. Gill membranes free from isthmus or attached, also sometimes delicate¬ 
ly united. Gill rakers well developed. Gills 4* ^ranchiostegals 5 to 11* 
Pseudobranchiae present or absent. Scales absent or very loose. Preorbital 
postorbital and ocular luminous organs single; on mandibular symphysis, in 
branchiostegal membrane and on body in groups; between isthmus and ventral in 
ventral and lateral series, between ventral and caudal in 1 series; body 
without smaller scattered luminous organs; no whitish punctiform organs on 
fins. Dorsal origin, which may be preceded by spines, median or postmedian, 
above or before anal origin. Adipose fin low, totally or partly above hinder 
part of anal, which may be divided. Centrals small, below or before dorsal 
origin. 
1 
a. 
1 
b» 
An abrupt ventral constriction between trunk and tail; no teeth on vomer; 
dorsal fin preceded by large triangular transparent plate* 
Eyes normal; space between trunk and tail filled by transparent integum¬ 
entary plate; anal not divided Sternoptyx# 
2 
b. Eyes telescopic; body hatchet shaped, ventral constriction without in¬ 
tegumentary plate; anal divided Argyropeleceus. 
2 
a. No abrupt ventral constriction between trunk and tail; eyes normal; 
teeth on vomer; dorsal fin preceded by forked spine; anal rot divided 
Polyip nus. 
Genus STENNOPTYX Hermann 
Sternoptyx HERI.IANN, Der Naturforscher, pt*16, 1781, p.33* Type Sternoptyx 
