214 
TEAVELS IN CENTEAL AFEICA. 
maxillary. The length of the head is one-fifth of the total or 
thrice the diameter of the eye. Eye without adipose membrane- 
Pectoral long, falciform, with the lanceolate scale in the axil short ; 
scale at the base of the spinous dorsal long, extending beyond the 
posterior spine. Caudal deeply forked, with the upper lobe longest. 
The single specimen observed is eight inches long. 
This is one of the few species which I do not know from autopsy ; 
the description is taken from Cuv. and Val., Vol. XI., p. 61. 
OPHIOCEPHALIDjE. 
Ophiocephalus. 
Body elongate, anteriorly subcylindrical, covered with smooth 
scales of moderate size; head depressed, covered with shield-like 
scales superiorly; lateral line well marked. Teeth in the jaws, on 
the vomer and palatine bones. One long dorsal and anal fin, with- 
out spines. V entral fins six-rayed, inserted below the pectoral fins. 
A cavity accessory to the gill- cavity. 
All the fishes of this family are fresh-water fishes from the East 
Indies, with the exception of one discovered by Mr. Petherick in 
the Upper Nile. It appears from recent observations that the 
amount of air which is in solution in the water is not sufficient 
