A NEW GENUS OF ACANTHOPTERYGIAN FISHES. 125 
measure one seventh of the total length: the height of the head is one half of its 
length. ‘The head is compressed on the sides and flat above. Its upper surface is 
narrow, the breadth of the cranium behind the eyes being scarcely one fifth of its 
length: from behind the eyes it becomes gradually narrower as it advances forwards 
to the nose, which is almost pointed. This surface is irregularly striated by ridges of 
bone, covered only by a thin skin, which radiate on each side from a point above the 
orbit. At the junction of the upper surface with the flattened sides of the head a 
strong keel or ridge is formed. In the small space intervening between this keel and 
the orbit the bone is cavernous, forming at its lower part, just behind the eye, a re- 
markable prominence. From behind this prominence there pass downwards to near 
the angle of the mouth, a series of small bones, producing on the smooth skin the ap- 
pearance of a double row of lengthened tubercles. The preoperculum is simple, forming 
aright angle with the upper line of the head. The operculum and suboperculum are 
strongly striated in a radiating manner. From the lower part of the series of small 
bones above noticed, the suborbital bones extend forwards to the nose in a narrow two- 
ridged line. The maxillary bone forms a line nearly parallel to the last ; is situated, 
like it, beneath the skin ; and borders the intermaxillary which constitutes the edge of 
the mouth. 7 
The intermaxillary bone on each side is slender and slightly toothed throughout its 
whole length: the anterior teeth, about six in number, are conical and stronger than the 
remainder ; those immediately succeeding are very small and very numerous ; they are 
followed by others of a larger size (but smaller than the anterior ones), to the number 
of about one hundred and ten, forming a single series, and resembling the teeth of a 
fine saw. The palatine bones, extending forwards to the front of the mouth and lying 
immediately within the intermaxillaries, are armed with very large and powerful lancet- 
shaped teeth, all of which have their points directed backwards. The anterior of these 
teeth are the largest: they equal in length one sixth of the entire length of the head. 
Of these there remain two on one side and one on the other ; and it is probable that 
their number has been two only on each side. Behind these, at an interval nearly equal 
to their length, succeed two teeth on each side, about half the size of the preceding. 
These are followed by six others of much smaller size, of which the anterior is the 
least ; they gradually increase in size, and the last of them is about one third of the 
length of the tooth immediately preceding the series. The posterior unarmed portion 
of the palatine bone in advance of the gape is about one eighth of the length. 
The lower jaw ceases to be armed nearly at the corresponding point. Its teeth, like 
those of the upper, are lancet-shaped. The anterior tooth is somewhat conical and 
is sharply pointed. It is succeeded by six others, of more compressed form, and of 
smaller size. These are followed by three large lancet-shaped teeth, increasing in size 
backwards, the hindermost equalling the largest of the two intermediate ones of the 
upper jaw. ‘These three larger teeth correspond, when the mouth is closed, with the 
s2 
