292 ACCOUNT OF A RIBBON FISH 
in the neighbourhood of the head by irregular depressed indu- 
rations of the skin. 
The head is small and short, measuring 9 in. from the snout 
to the posterior margin of the gill-cover ; the outline of the 
lower jaw is a wide arch convex below, and stretching forwards 
and upwards to the mouth, which is placed in an elevated posi- 
tion and opens upwards and forwards ; the mouth is small, near- 
ly circular, and capable of being projected 2 or 3 in. forwards 
when the lower jaw is depressed. The profile of the head from 
the anterior end of the crest is at first suddenly concave, the con- 
cavity facing forwards and upwards, and just behind the anterior 
end of the curve exists the nasal chamber which is small, and 
owing to the damaged state of the fish we could only find one 
small aperture, which was longer than it was broad. Beyond 
this concavity the premaxillary bones project nearly horizontally 
to the mouth. The eye is 13 in. in diameter, the iris of a beau- 
ful silvery white, and rather broader than the diameter of the 
pupil. The eye is situated 24 in. below the base of the crest and 
13 in. behind the frontal concave profile. There is a narrow im- 
perfect circle of a dusky colour round the contour of the eyeball. 
The eye is very flat. The tongue is rather prominent, but small, 
smooth and fixed. There are no teeth. The interior of the 
mouth is black. 
The gill-covers are large in proportion to the size of the head, 
prolonged backwards, their posterior angles considerably ele- 
vated. The preoperculum has somewhat of a crescentic form, 
the lower border convex ; the anterior horn is narrow and pro- 
longed to its articulation with the lower maxilla, the posterior 
border has an obtuse angle pointing backwards. This border 
corresponds to, and may rest upon, the edge of the concavity 
formed by the operculum above and the interoperculum below. 
The operculum is on the whole broad and irregularly quadrate, 
with the upper anterior angle prolonged forwards and upwards ; 
the upper margin is smooth and slightly concave nearly as far as 
the angle, it then curves suddenly downwards a little to the 
angle which is rather obtuse. Below this is the posterior border, 
