156 The Apodes, or Eel-like Fishes 
wanting, as in all true eels, and the maxillaries loosely joined 
to the skull. The symplectic bone is wanting, and the lower jaw 
is so hinged to the skull that it swings freely in various direc- 
tions. In place of the lateral line are singular appendages. 
Fig. 116.—Derichthys serpentinus Gill. Gulf Stream. 
Dr. Gill says of these fishes: ‘‘ The entire organization is peculiar 
to the extent of anomaly, and our old conceptions of the char- 
acteristics of a fish require to be modified in the light of our 
knowledge of such strange beings.’’ Special features are the 
extraordinary size of the mouth, which has a cavity larger than 
that of the rest of the body, the insertion of the very small 
eye at the tip of the snout, and the relative length of the tail. 
The whole substance is excessively fragile as usual with animals 
living in great depths and the color is jet black. Three species 
Fra. 117.—Gulper-eel, Gastrostomus bairdi Gill & Ryder. Gulf Stream. 
have been described, and these have been placed in two families, 
Saccopharyngide, with the trunk (gill-opening to the vent) much 
longer than the head, and Eurypharyngide, with the trunk very 
short, much shorter than the head. The best-known species 
is the pelican eel (Eurypharynx pelacanoides), of the coast of 
Morocco, described by Vaillant in 1882. Gastrostomus bairdi, 
very much like it, occurs in the great depths under the Gulf 
Stream. So fragile and so easily distorted are these fishes that 
