348 DESCRIPTIONS OF APODAL FISHES — GILBERT. 



Head 2| iu body (bead and trunk) ; the body 3^ in tail. 



Dorsal begiiiniug behind the head at a distance equaling one fourth 

 the length of head. 



Color dusky-olive, dotted with coarse brown specks everywhere ex- 

 cept on under side of head and on fins. A blackish streak on median 

 line of belly. Fins translucent. 



This species has not the appearance of a deep-sea eel, though the 

 intestine is protruded through the anus in the type specimen, as the 

 result of the release of pressure. A single specimen 14i inches long, 

 said to have been taken at Station 2793, oft" the coast of Ecuador, iu 

 401 fathoms. 



Xenomystas gen. no v. (MuraenesocidsB.) 



Scaleless. Pectorals well developed. Vertical fins large, continuous 

 around the tail, the rays evident. Dorsal beginning before base of 

 pectorals. 



Grill slits vertical and rather wide, the gill membranes continuous be- 

 low the throat. 



Branchiostegals apparently eleven or twelve in number, long and 

 much curved, continuing around the posterior and upper edges of 

 opercles. Mouth with wide lateral cleft, not extending far beyond 

 the eye. Maxillary very wide, not extended far forwards, the clasping 

 processes applied to shaft of vomer well behind its head. 



Teeth all conical, slender, and sharp, mostly depressible, those in 

 jaws in wide bands. Maxillary with a deep lengthwise groove, running 

 the entire length of bone and dividing the band of teeth into two por- 

 tions. Lower jaw much shorter than the upper. 



Posterior nostril a linear slit, midway between eye and tip of snout; 

 the anterior in a short tube just behind the head (-f vomer. Tongue, 

 small, with the tip free. Lips undeveloped. Lateral line conspicuous. 



A deep-water form, with thin skin and black coloration, most nearly 

 related to Mnrcvnesox, but differing in the peculiar structure of the jaws 

 and in the dentition. 



(Type, Xenomystax atrarius sp. nov.) 



Xenomystax atrarius, sp. uov. 



Snout very long and slender, the gape wide ; end of maxillary equi- 

 distant from tip of mandible and gill opening. Front of orbit over the 

 beginning of last third of length of gape. A series of long slit-like mu- 

 cous pores along margin of upper jaw ; a conspicuous series on mandi- 

 ble and preopercle. 



Teeth in jaws in wide bands, mostly depressible, the outer series of 

 teeth laterally shortest and not meeting in closed mouth. The maxil- 

 lary teeth divided by a deep groove running entire length of jaw, 

 those on inner side of groove long, close set, rigid, in a single series. 

 Mandible with a much narrower and shallower groove, on the inner 

 edge of which is a single series of very small conical teeth, directed 



