628 FISHES. 



These small fishes are now and then picked up in the 

 Mediterranean and Atlantic. According to the dredging- 

 records of the " Challenger," they and the allied genera Argy- 

 ropelccus and Polyipnus would descend to depths of respectively 

 1100 and 2500 fathoms ; but the form of their body and their 

 whole organisation render this statement very improbable ; 

 they most likely live at a small depth during the day-time, 

 coming to the surface at night, like many Scoioelus. 



Coccia and Maurolicus are two other genera allied to the 

 preceding. 



Chauliodus. — Body elongate, compressed, covered with ex- 

 ceedingly thin and deciduous scales ; series of luminous (phos- 

 phorescent) spots run along the lower side of the head, body, 

 and tail. Head much compressed and elevated, with the bones 

 thin, but ossified, and with the opercular portion very narrow, 

 the interoperculum being rudimentary. Cleft of the mouth ex- 



Fig. 2S5. — Chauliodus sloauii. 



ceedingly wide, the intermaxillary forming one half of the upper 

 jaw. Each intermaxillary with four long canine teeth ; edge of 

 the maxillary finely denticulated ; mandible with pointed, widely 

 set teeth, the anterior of which are exceedingly long ; none of 

 the large teeth are received within the mouth. Palatine with a 

 single series of small pointed teeth ; no teeth on the tongue. 

 Eye of moderate size. Pectoral and ventral fins well developed. 

 Dorsal fin anteriorly on the trunk, before the ventrals ; adipose 

 fin small, sometimes fimbriated ; anal short, rather close to the 

 caudal, which is forked. Gill-opening very wide, the outer 

 branchial arch extending forward to behind the symphysis of 

 the lower jaw; it has no gill-rakers. Branchiostegals numerous. 



