into very long and strong tusks, and considerably exceed the other
teeth in size. They are supported on strong tumid processes of the
jaws, with which their bases are firmly anchylosed. In the jaws
represented at fig. 1, one of the large teeth has been shed, and the
cavity is laid open to expose its successor, of which the crown is
partly formed. Similar new teeth, preparing to take the place of the
smaller lateral laniaries, are exposed in their cavities. These reserve
teeth are situated above and a little to the outside of the base of the
tooth, which they are destined to displace ; and, in the more advanced
examples, a perforation leading to the cavity may be seen on the
outer side of the old tooth. Absorption of the anchylosed base of
the tooth commences at this part, and gradually extends inwards.
In fig. 2, an inside view of the jaws of the left side is given, to
show the pavement of minute rounded denticles along the inner side of
the bases of the laniary teeth. The jaws are of great strength in
relation to the force with which the teeth are destined to be exerted.
In the Dentex hexodon only six of the teeth in each jaw present
the laniary figure and size, the rest being small and closely aggregated
in a comb-like form. The tongue and palate are quite smooth, the
bones of these parts, as well as the vomer, being edentulous. The
pharyngeal bones, from the small size of their numerous teeth,
resemble fine combs.
The Dentices devour small fishes, cephalopods and Crustacea;
their intestinal canal is short, the pyloric caeca few, and the stomach
simple and membranous. They frequent rocky places.
37. The gilt-heads (Chrysophrys) are distinguished by a dentition on
the same general teleological principle as in the Cestracion and Anar-
rhicas, the anterior teeth being adapted for seizing, and the posterior
ones for crushing the alimentary substances. These teeth are limited
in their position to the intermaxillary and premandibular bones.
The elongated conical anterior teeth are never fewer than four, or
more than six in each jaw. The posterior obtuse rounded grinding
teeth, are arranged in three or more rows.
In the species of Gilt-head, (Chrysophrys Australis), of which the
jaws are figured in Plate 42, fig. 3, the principal or long anterior
conical teeth are four in each jaw ; those of the,lower are more widely
separated than those of the upper jaw, and in the interspace of the two
middle ones of the lower jaw, there are two small conical teeth. In
the upper jaw, the first tooth of the external row of molar teeth,
presents a conical crown | the rest are rounder and more obtuse, but
present a small mammilloid apex; after the eighth, there are three
or four much smaller teeth. The molar teeth of the second row are
less than the outer ones ; some much smaller granulated teeth, less
regular in their arrangement and size, are developed at the inner side
of the base of the second series. The principal molars of the lower
jaw are also in two rows, internal to which are some smaller and
less regular teeth, which are fewer in number than those of the
upper jaw.
There is a constant and pretty quick succession of teeth in the
jaws of the gilt-heads. In the specimen figured, the outer plate,
of the intermaxillary and maxillary bones has been removed to
show the successors of the outer row of teeth, in various stages of
formation, but with the crown of the tooth nearly completed in most
of them. These germs are each lodged in a cavity close to the base
of the tooth which is to be replaced ; their course is directed towards
the outside of that base, and the cavity, which is occasioned by the
absorption consequent on the pressure, is enlarged from without
inwards, contrary-wise to the progress of the excavation which is produced
in the succession of the teeth of the Reptilia.
The matrix of the teeth of the Chrysophrys, as in most other
fishes, becomes ossified when the crown of the tooth is fully completed
; and the tooth is thus fixed by anchylosis to the margins of the
jaws.
In the present and many other exotic species of Chrysophrys, the
new teeth alwavs resemble in shape and size those which they succeed
; but in our common gilt-head (Chrysophrys aurata), some of the
posterior and internal molars, which in the young fish are hemispherical,
are succeeded in the mature fish by one or sometimes two
larger grinders of an oval form.
In this species there are six holders, or produced anterior teeth,
in each jaw ; they are relatively stronger, longer, and more curved
than in the Chrysophrys Australis. The obtuse grinding teeth are