HALIBUT. 
411 
a distance from the tip of the snout that is about equal 
to the longitudinal diameter of the eyes. The nostrils 
of the blind side are set at the same distance from the 
tip of the snout and in the same relative position to 
each other, the anterior being also furnished posteriorly 
with a more or less nearly semitubular dermal flap; 
and are situated at the upper margin of the head, 
where the coloration of the eye side generally extends 
some way over the blind side. The jaw-bones of both 
sides of the . body are fairly similar to each other in 
shape, and show a great likeness to the corresponding 
bones in the Gad idee. The greatest asymmetry appears 
in the intermaxillary bones, the length of the inter- 
maxillary bone of the eye side being sometimes only 
4 / 3 of that of the intermaxillary bone of the blind side. 
The nasal processes of these bones project above their 
upper margins 1 f i (on the blind side) or 1 / 3 (on the 
eye side) of the length of the bones themselves. Behind, 
in their upper margin — at two thirds of the distance 
along the intermaxillary bone of the eye side and half- 
way along that of the blind side — they are raised 
into a, sharp projection, which evidently corresponds to 
the upright, more or less lobate process on the hind 
part of the intermaxillary bones in several Gadoid spe- 
cies. The maxillary bones are furnished with a similar 
but more process-like projection at the upper margin, 
at the end of the first third of their length. These 
bones differ only slightly from each other on both sides 
of the body, and the broadened hind extremity of the 
maxillary bone of the eye side extends back to a point 
almost vertically below the anterior margin of the pu- 
pil of the lower eye, or, in older specimens, below the 
middle of this eye. The branches of the lower jaw 
are also much alike, the length of that of the eye side 
being at least 92 — 97 % of that of the blind side; and 
their length, which is about 11 or 12 % of the length 
of the body, is always somewhat less than half that of 
the head. The jaw-teeth resemble the teeth of a snake, 
and in old specimens are set in several rows — in the 
lower jaw as many as 4, and on the front of the inter- 
maxillary bones 5 — but in young specimens they are 
set in a single row in the lower jaw, and in two rows 
only at the extreme front of the intermaxillary bones. 
The pharyngeal teeth are like the jaw-teeth. On the six 
upper pharyngeals (three on each side) they are set in 
transverse rows, two rows on each bone or, in old spe- 
cimens at least, three rows on each of the middle pair. 
On each of the lower pharyngeals, which resemble 
branchial arches, the teeth are set in two longitudinal 
rows, the outer row being composed of smaller but 
more numerous teeth. The gill -rakers are comparatively 
short and scattered, but strong and denticulated. They 
are set in a single row and almost exclusively on the 
lower part of the anterior margin of the branchial 
arches. On the first arch, however, which is furnished 
with from 7 to 9 gill-rakers, one of the latter, more 
like a tubercle than a spine, is sometimes set on the 
upper part. Even Kroyer remarked the small, denti- 
culated splinters of bone, arranged more or less re- 
gularly in squares, that lie in the skin beside the 
branchial arches themselves, and render the latter rough 
to the touch. These splinters are usually most distinct 
on the outside of the lower pharyngeals. The hind 
(lower) part of the urohyoid bone is sharply falciform, 
with the point directed forward, as usual; and is almost 
as long as the straight anterior (upper) part of this 
bone. The entire bone lies free, almost half-way be- 
tween the clavicular and the hyoid bones, united by 
muscles to the front of the lower end of the former 
and by a round ligament, as usual, to the under sur- 
face of the latter. The distance between its lower end, 
which is curved forward, and the lower end of the 
clavicular bone is about equal to the distance between 
the latter and the first ray of the ventral tin. Within 
its rounded angle, open in front, lies the middle part 
of the margin of the branchiostegal membrane, which 
is united from each side of the body, but with this 
exception free. The branchiostegal membrane and its 
rays — 7 on each side, the two anterior ones being 
partly united at the tip — conform to the usual Hete- 
rosomatous type. The gill-openings extend upwards to 
a level with the inferior margin of the upper eye. The 
operculum forms an equilateral triangle, with the upper 
posterior side convex and the lower posterior concave, 
and in this sinus lies the suboperculum, which is 
pointed at the top, and juts upwards almost into the der- 
mal opercular Hap. The preoperculum is rectangular, 
but the angular point is evenly rounded, without any 
distinct acuteness. The postorbital part of the head 
measures between about 14 and 15Va ° /o °f the length 
of the body. 
The dorsal fin begins above the anterior part of 
the upper eye, usually in a line with the anterior 
margin of the pupil, in other cases somewhat in front 
of this point or at a distance from the tip of the snout 
that measures 6 x / 2 or 7 % °f the length of the body, 
