PISCES. 
pte, remain for a long time only attached 
y suture to the bodies of the vertebra, from 
which they are easily distinguished. 
In certain Fishes, as, for example, in Merlus, 
the transverse processes are very large and give 
attachment to the swimming bladder. Some- 
times the ribs are suspended from the trans- 
verse processes, or sometimes they are derived 
immediately from the bodies of the vertebra. 
In this respect there are great varieties. 
In those vertebre that are situated behind 
the abdominal cavity there is an inferior fora- 
men for the lodgement of the great blood- 
vessels of the trunk bounded by inferior spinal 
lamin ( hemapophyses ), and, like the superior, 
generally supporting long spinous processes, 
(fig. 493, 5,) so that the vertebrae seem to consist 
of similar parts, both above and below the body. 
These inferior arches of the caudal vertebra 
are considered by Cuvier as being formed by 
the inordinate developement of the transverse 
processes, which he describes as here becom- 
ing directed downwards and united to each 
other, so as to form the inferior ring; and, 
certainly, in the generality of Fishes, by tra- 
cing the apparently gradual conversion of the 
abdominal into the. caudal vertebre, such is 
the conclusion at which the comparative anato- 
mist would naturally arrive. In many Fishes, 
however, as, for example, in the Murenide, 
these inferior arches with their appropriate 
— are in the caudal region co-existent with 
istinctly developed transverse processes, evi- 
dently shewing that they must be regarded as 
being totally different elements of the skeleton, 
namely, the hemapophyses. (See Osszous 
System.) 
The inferior or heemapophysial elements, like 
the superior arches, have in many instances 
oblique processes developed from tlem, which 
in some cases are very large and branched, so 
as to form a kind of interlacement around the 
vascular canal. This is especially observable 
in certain Tunnies. 
As the vertebre approach the tail, their pro- 
cesses are gradually shortened, and the verte- 
bral canal becomes narrowed or obliterated, 
(fig. 493, 8,) and at length the terminal vertebra 
have their apophyses consolidated with each 
other and with the interspinous bones, so as to 
form in some Fishes, as the Perch, a vertical 
triangular plate, to the posterior margin of which 
are articulated the rays of the caudal fin (9). 
In Fishes with long and pointed tails like the 
Eels this disposition is wanting; but in other 
races, such as the Pike, the real composition of 
this part of the skeleton is easily recognisable. 
Ribs and sternum.—The ribs of Fishes have 
nothing to do with respiration, merely serving 
to support the muscular parietes of the body ; 
they consist of the dorsal portion only, which 
is articulated by a single head, either to the 
transverse processes or to the bodies of the 
vertebre themselves. Frequently they give off 
long bony processes, which penetrate among 
the muscles; and sometimes also similar pro- 
cesses are attached above the ribs to the bodies 
of the vertebre themselves, so that the flesh of 
-some Fishes appears full of little bones as fine 
959 
as hairs. The ribs vary extremely in different — 
genera. Sometimes they are round and slen- 
der, sometimes compressed and _falciform ; 
occasionally they seem to surround the whole 
abdomen, and in many species are quite rudi- 
mentary or altogether wanting. The sternum 
is entirely deficient in most Fishes; sometimes, 
however, it does exist, as in Clupea, Vomer, 
&c.; in such cases it consists of a longitudinal 
series of impair bones, differently shaped in 
different genera, to the sides of which the ribs 
are attached inferiorly. 
Cranium.—The cranium of osseous Fishes, 
when all its parts are completely developed, is 
made up of no fewer than twenty-six bones, six 
of which are azygos, viz. the basilar, the principal 
sphenoid, the anterior sphenoid, the vomer, the 
ethmoid, and the interparietal or superior occi- 
pital; and twenty are in pairs, namely, the 
JSrontal, the anterior frontal, the posterior pre 
tal, the parietal, the mastoid, the external occi- 
pital, the lateral occipital, the petrous, the great 
alar and the lesser alar bones; but as these 
have all been described and figured in a pre- 
ceding article, and their homologies with the 
cranial bones of the other vertebrate classes 
fully discussed, (vide Ossrous System, Comp. 
Anat., vol. iii. p. 826,) it would be superfluous 
to dwell upon them more at length in this place. 
Bones of the fuce.—The bones of the facial 
apparatus have likewise been pointed out and 
figured in the article above referred to. They 
consist, when the series is complete, of the fol- 
lowing pieces, which, seeing the extremely vari- 
ous forms of the face in this class of animals, 
present innumerable varieties as regards their 
developement and relative importance, notwith- 
standing that their general arrangement is tole- 
rably persistent throughout the class. 
The mazillary (fig. 436, 18, vol. iii. p. 826) 
and the intermazillary (fig. 436, 17) form the 
anterior boundaries of the face and circumscribe 
the anterior and lateral limits of the mouth: the 
latter, however, is in Fishes the most important 
bone of the two, and is most commonly armed 
with teeth, while the former is very generally 
destitute of dental organs, and being imbedded 
in the fleshy substance of the upper lip, has been 
called by some authors the labial bone or os 
mystacis. It is indeed upon the relative shape 
and size of the intermaxillary bone that the 
form of the upper jaw of Fishes principally de- 
pends, and in some cases, as for example in 
the Sword-fish (Xiphias), Lepidosteus, &c. these 
bones are enormously pamonaee anteriorly, so 
as to form an elongated beak or powerful ros- 
trum which constitutes a formidable offensive 
weapon. 
e face of Fishes, properly so called, is 
made up of several bony pieces very variable 
both in their size and number, which have been 
named the prenasal (fig. 436, 20,) the subor- 
bital (fig. 436, g, g, g,) and the supra-temporal 
bones ; all of these, however, with the exception 
perhaps of the prenasal, belong to the exoske- 
leton (vide vol. iii. p. 845.) In the hard-cheeked 
Fishes (“ joues cuirassées” of Cuvier) these 
osseous plates are enormously developed, and 
indeed form a kind of bony mask enclosing all 
