69 
the vomer is acute and projects a little. The orifice of the mouth is 
rather larger than in the Cheilodactyli, but the jaws are extensible in 
about the same degree. The maxillary bone wants the flat thin plate 
near its head which exists in the Cheilodactyli and glides beneath 
the preorbitar. The latter bone is narrow, its width not being ecpial 
to one-third of the diameter of the orbit. The eye is comparatively 
large, three diameters and a half of the orbit being equal to the entire 
length of the head, and two of these diameters measure the distance 
between the hinder edge of the orbit and the tip of the gill-cover. 
The position of the eye is high enough to encroach upon the profile. 
The cheek equals the diameter of the orbit in breadth ; the disk of 
the preoperculum is also wide, and the inter operculum moderately so. 
The operculum and suboperculum conjointly have a triangular form ; 
the former is notched, and the latter is prolonged by a membranous 
tip, which forms the apex of the gill-cover. Both these bones are 
densely scaly; there is also a row of scales on the interoperculum, 
partially overlaid by the thin edge of the preoperculum, and the tem¬ 
ples are also scaly. The rest of the head is without scales, but the 
mucous skin, full of canals and pores, which envelopes the head, pre¬ 
vents us from ascertaining the exact extent of the scales, at least in 
the dried specimens. The top of the head is destitute of scales to the 
occiput, but in the Cheilodactyli , dense, small scales extend forward 
on the skull to before the eyes. In the absence of thick fleshy lips, 
the genus differs from Cheilodactylus. The preorbitar is neither wide 
enough nor long enough to conceal the maxillary, which however 
enters partially beneath its edge. The thin crescentic border of the 
preoperculum is striated, but not crenated. The same kind of streaks 
or furrows may be discerned, though not so readily, in some Cheilo¬ 
dactyli. The head forms a fourth of the total length. The height 
of the body is also equal to a fourth of the length of the fish, caudal 
included. The belly is prominent, and the tail, posterior to the ver¬ 
tical fins, is slender. The lateral line is straight, and each of its scales 
is marked by a short straight tube, which is placed somewhat obliquely 
to the general direction of the line. About fifty-two scales compose 
a row between the gill-opening and caudal, the base of whose rays are 
also scaly, and the lateral line is prolonged as far as the scales extend 
on that fin. 
The dorsal commences over the upper angle of the gill-opening and 
reaches to within an inch of the caudal. Its seventh spine, which is 
the tallest, is nearly equal to half the height of the body; the others 
are graduated very slightly posteriorly and more rapidly anteriorly. 
None of them are stout, and all of them are traversed on each side 
by a deep furrow. The membrane between them is deeply notched, 
as in the genus Pelors , and a slender process running up the back of 
each spine surmounts it in form of a small free lobe. The soft rays 
surpass the tallest spine a little, and are more than twice the height 
of the last one. The anal commences opposite to the beginning of 
the soft portion of the dorsal and ends beneath its tenth branched 
ray, or, in the specimens before us, about two inches and a half from 
the caudal. The spines are like the dorsal ones, grooved and slender, 
