632 
SCANDINAVIAN FISHES. 
ryngeals like branchial arches, only shorter and thicker 
than the ceratobranchial 1 tones, and furnished with 
three rows of teeth, the outermost consisting of cylin- 
drical teeth, the middle row of pointed ones, but all 
these teeth considerably shorter than those of the inner- 
most row, which are larger, compressed, and claw-shaped. 
Two of the three upper pharyngcals are thick and united 
into one bone, which bears two rows of claw-shaped 
teeth, at the base broad but compressed, at the tip 
sharply pointed. The skeleton of this species contains 
7 abdominal and 10 caudal vertebrae, including the 
urostyle. 
Within the subfamily of the Balistince, of which 
about 30 species have been described, Bleekee esta- 
blished 4 genera, differing in the form of the base 
of the caudal fin and in the form and colour of the 
jaw-teeth. The forms are so closely allied, however, 
that a division into genera can be defended only as an 
expedient to facilitate a general survey of the subfamily. 
Among the peculiarities of the skeleton, besides 
those mentioned above, the strong supporting apparatus 
of the first dorsal fin, with the articulation of the first 
spinous ray, which is the principal defensive weapon of 
these fishes, is especially remarkable. The supporting 
apparatus, which is evidently formed by the coalescence 
and more advanced development of the elements of the 
first interspinal bones, consists of three bones", the hind- 
most of which is wand-like and lies in a backward and 
downward direction, so that its hind extremity rests 
against the lower part of the first interspinal bone of 
the second dorsal fin — which bone is here supported 
on the front of the upper spinous process (neural spine) 
of the fifth abdominal vertebra — while the anterior 
(upper) extremity articulates firmly with the lower 
end of the middle bone in the supporting apparatus. 
This bone is triangular, with one angle directed down- 
wards, but longitudinally cloven, its two wing-like 
halves forming an angle open above and being firmly 
united in front and below to the first and largest bone 
in the supporting apparatus. This last bone is can ali- 
en late, but its long bottom is sharply carinated, thus 
forming together with the middle bone a kind of boat, 
with the bows pointing backwards and split (open) and 
with a large, elliptical hole — crossed, however, by a 
narrow, transverse bridge of bone — in the posterior 
part of each side, but with the middle of its stern 
(turned forward in the fish) touching the middle ridge 
of the cranium ( s-pina occipitalis) above the hind part 
of the orbits. The hind part of the gunwale (in the 
fish the fore part) is furnished with articular cavities, 
one on each side, for the lateral articular processes of 
the first spinous ray, and from the middle of the bottom, 
in the stern, rises a tap-like process with rounded 
head, over which glides the base of this ray, with 
its concave centre. In front of this process (i. e. 
behind it in the longitudinal direction of the fish) rises 
from the keel of the boat another tap-like and round- 
topped process, over the head of which the cloven base 
of the second spinous ray glides to and fro. The back 
of the first spinous ray is concave (canaliculate). The 
front of the second spinous ray is tumid at the base, 
and this swelling drops into the groove of the first spi- 
nous ray, when the rays are erected. In this manner 
the first ray is locked fast, and any attempt to force it 
back merely exerts a pressure on the second ray, which 
is thus kept all the more firmly fixed to its tap-like 
articular process, and effectually hinders any backward 
curvature of the first ray. In order to attain this result 
the second spinous ray must be drawn back, an opera- 
tion which is performed partly by means of special 
muscles, partly by a ligament which unites this ray 
within the fin-membrane to the third spinous ray * 6 . In 
the Monacanthince , which are without the third spinous 
ray, the supporting apparatus is also less developed; 
and in the Triacanthince the first interspinal bones are 
only slightly metamorphosed. 
“ Cf. Hollard, Ann. Sc. Natur., troisieme serie, Zoolog., tom. XX, p. 102; Sorensen, Om Lgdorganer hos Fiske, p. 50. 
6 Hence, according to Johnston ( De Piscibus, p. 110), the generic name of Batistes (catapult). The Italians, he says, called one of 
these fishes pesce balestra , because a slight pull at the third spinous ray was enough to overcome the rigidity of the first ray and to depress 
it, just as a light touch of the hammer or trigger in the lock of a cross-bow sufficed to discharge the weapon. This name reappears in the 
English name of Trigger- fishes as applied to these forms. Batistes was introduced into zoological nomenclature, without any special explana- 
tion, by Artedi, first in Seba’s Thesaurus , tom. 3, p. 63 and again in Gen. Piscium, p. 53. 
