DISCUSSION OF SPECIES AND THEIR DISTRIBUTION. 137 



Nip scales, Jaws even. Tee1 li present or absenl on vomer Lepto* i ph \i id i 



Scales present, minute. Lowerja'H projecting. Vomerine teeth [Anguilli 



b. Gill openings horizontal, inferior. Scales present. Lips obsolete, or marly so. 



' Snout obtuse. Jaws powerful. Teeth in jaws blunt, uniserial, with none on vomer. 



SlMlMlll l.l ID e 



" Snout conical, .laws moderately strong. Teeth sump, in bands in jaws and on vomer. 



Il/i ■ ti-u 1 1 > 1: 

 2. Gill openings inferior and confluent, 

 a. Head conical ; tongue small. 



' Posterior nostrils close to eye. Branchiostegals shortened Synaphobrani jiih.i: 



1$. Pectoral lins absent. 



1. GiU openings distinct, lateral. Scabs wanting. Mouth oblique, with projecting lower jaw 

 and sin lit obtuse snout. 



a. Body and tail very elongate. Teeth in bands in jaws and on vomer Betekocongridj 



II. Tongue narrow, not free. No scales. 

 Gill openings rather wide. 

 A. Pectorals strong. 



1. End of tail normally surrounded by vertical fins. Skeleton linn. Skin thick. 



a. Jaws model ate. Vomer dentigerous Mi'r.isi -mm ii> i 



' Dorsal and anal well developed Huroenesoeince 



* Vertical fins scarcely developed except on tail [Stilbiscina;.] 



li. Pectorals moderate, weak, or absent. 



1. End of tail more or less free. 



a. Posterior nostrils in lip or near it; anterior ouo sometimes tubular OPHICHTHYID E 



* Fins present, at least on back Ophichthyince 



** Fins absent Sphagebranchinoe 



2. Tip of tail more or less surrounded. 



a. Dorsal well developed; peetorals sometimes united Myrincc 



Gill openings small, subinferior. 

 A. Peetorals lacking. 



1. End of tail prolonged in a filament. Skin thin. Skeleton weak. 

 a. .Taws straight, slender, the upper longest. 



' Teeth sharp, recurved. Vomer with a long series NETTA8TOMTD.fi 



Gill openings convergent forward, separate or confluent. 

 A. Pectorals present (in American genera i. 



1. Jaws very long, recurved at tip NEMICHTHYID i 



Family LEPTOCEPHALID^E. 



Congerida, Katjp, Cat. Apodal Fish, in Brit. Mus.,1856, 108. 

 Congridce, Jokdan & Davis, Rep. V. s. F. c, 1888 (1891), 658. 

 Leptocephalida, Gill, Ms. 



Body terete, moderately elongate, with the tip of the tail included between the connate 

 vertical lins. Scales absent. Head large, with strong equal jaws. Tongue broad, its ante- 

 rior portion comparatively free. Opercular and branchial bones well developed. Vomerine 

 teeth moderate. Anterior nostril remote from eye. Posterior nostril, near the eye, tube- 

 less, not touching the lip. Pectorals, well developed. 



This family includes those eels which are scaleless and have the tongue largely free 

 in front, the body moderately elongate, the end of the tail surrounded by a fin, the posterior 

 nostril remote from the upper lip and near front of eye, and the pectoral fins well developed. 

 All the species are plainly colored, grayish or dusky above, silvery below, and have the 

 dorsal edged with black. 



KKV TO THE GENERA OF LEPTOCEPHALIDA. 



I. Vomerine teeth in bands, uniform in size; lips thick. 



A. Dorsal origin behind root of pectoral. 



1. Jaws with outer knife-like row of closely set teeth, Head with inconspicuous mucous 

 cavities, 

 a. 'fail considerably longer than body - [ Leptocephali s ( Iongee] 



B. Dorsal origin over the gill opening. 



1. Jaws with bauds of small teeth, the outer not forming a cutting edge. Bones of front of bead 

 with large muciferous cavities. 

 a. Tail one-half to two-thirds of total. Mouth rather small CONGEBHU&SNA 



