548 FISHES. 



Ventrals reduced to simple filaments placed close together on the 

 humeral symphysis. Scales extremely small. Bones of the 

 head soft. 



Only two specimens, thirteen inches long, of this remark- 

 able deep-sea form have been obtained, at a depth of 1075 

 fathoms, in the Indian Ocean. 



Typhlontts. — Head large, compressed, with most of the 

 bones in a cartilaginous condition ; the superficial bones with 

 large muciferous cavities, not armed. Snout a thick protuberance 

 projecting beyond the mouth, which is rather small and inferior. 

 Trunk very short, the vent being below the pectoral ; tail thin, 

 strongly compressed, tapering, without separate caudal. Eye 

 externally not visible. Villiform teeth in the jaws, on the vomer 

 and palatine bones. Barbel none. Scales thin, deciduous, 

 small. 



Also of this deep-sea fish two specimens only are known, 

 10 inches long, from a depth of 2200 fathoms in the "Western 

 Pacific. 



Aphyonus. — Head, body, and tapering tail strongly com- 

 pressed, enveloped in a thin, scaleless, loose skin. Vent far 

 behind the pectoral. Snout swollen, projecting beyond the wide 

 mouth. No teeth in the upper jaw, small ones in the lower. 

 No externally visible eye. Barbel none. Head covered with a 

 system of wide muciferous channels, the dermal bones being 

 almost membranaceous, whilst the others are in a semi-cartila- 

 ginous condition. Notochord persistent, but with a superficial 

 indication of vertebral segments. 



Fig. 252. — Aphyonus gelatinosus. 



One specimen only of this most remarkable form is 

 known ; it is 5| inches long, and was obtained at a depth of 

 1400 fathoms south of New Guinea. 



