284 Isospondyli 
As in the Osteoglosside and in the Siluride, the subopercle is 
wanting in Pantodon. 
The Alepocephalide are deep-sea herring-like fishes very 
soft in texture and black in color, taken in the oceanic abysses. 
Some species may be found in almost all seas below the depth 
Fig. 217.—Alepocephalus agassizii Goode & Bean, Gulf Stream. 
of half a mile. Alepocephalus rostratus of the Mediterranean 
has been long known, but most of the other genera, Talis- 
mania, Mitchillina, Conocara, etc., are of very recent discovery, 
having been brought to the surface by the deep-sea dredging 
of the Challenger, the Albatross, the Blake, the Travailleur, 
the Talisman, the Investigator, the Hirondelle, and the Vio- 
lante. 
