smaller ones in the interspaces, with the
bases of two of the larger teeth showing
the convergence of the peripheral fissures
towards the centre of the tooth. The
end view of the section shows the alveolar
groove and its outer parapet. Fig. 2.
Parts of the lower jaw of a fossil Sauroid
(Holopty chius Hibbertii, Agas. Rhizodus
mihi) : a, implanted and anchylosed base
of one of the large teeth. Original.
PLATE 36.
One of the large laniary teeth of the
natural size, with a longitudinal section
removed from the base, and a magnified
view of the section : Rhizodus Hibbertii,
Original. (A transverse section
shows the radiations of the divisions of
the pulp-cavity continued into the cylindrical
processes of the base of the tooth,
according to the labyrinthic type of structure.)
PLATE 37.
A portion of a transverse section of the
crown of one of the large laniary teeth
of Rhizodus Hibbertii. These teeth and
the analogous ones of the recent Sauroid
fishes differ from the teeth of the
Labyrinthodon in the larger proportion of
the crown in which the pulp cavity is
simple, as in the figure. Original.
PLATE 38.
Fig. 1.—Lower jaw and dental masses
of the Globe-Fish (Diodon Hystrix).
Fig. 2. Portion of the same cleft
vertically near the symphysis; a, the
last formed plates of the posterior tooth:
b, the same of the anterior tooth: c,
the intervening vascular canal. Fig. 3,
A portion of a section of the posterior
tooth magnified 600 linear diameters : a,
intervening layer of osseous or cemental
substance ; between b and c the dentinal
layers of the compound tooth. Original.
PLATE 39.
Fig. 1. Jaws of the Tetrodon lineatus.: a,
posterior lamelliform teeth of upper
jaw. Fig. 2. Portion of a vertical section
of the posterior tooth of Diodon
Hystrix magnified 120 linear diameters.
PLATE 40.
Fig. 1.—Side view of intermaxillary and
mandibular teeth of a File-Fish (Balistes
forcipatus). Fig. 2. a, upper, b, lower
pharyngeal bones and teeth, left side, of
Balistes forcipatus. Fig. 3. Outside
view of right intermaxillary, showing
the alveoli for the union by double gom-
phosis of the outer teeth. Fig. 4. Inside
view of the same, showing the inner
teeth. Fig. 5. Successional intermaxillary
teeth exposed : a, osseous tubercle
which supported the tooth in place : b,
the end of the successional tooth which
has caused the absorption of the osseous
tubercle of the second intermaxillary
tooth. Fig. 6. Successional teeth of the
inner row exposed. Fig. 7. Inner surface
of teeth of the lower jaw. Original.
PLATE 41.
Fig. 1.—Upper and lower jaws and teeth
of a Sea-Bream (Dentex Argyrozona),
Fig. 2. Inside view of those of the left
side : a, intermaxillary: b, maxillary :
c, dentary : d, articular.
PLATE 42.
Fig. 1.—Upper view of the teeth of the
lower jaw of Sargus rufescens. Fig. 2.
Front view of incisors of a young Sargus
Vetula. Fig. 3. Upper and lower jaws
and teeth of a Gilt-Head (Chrysophrys
australis). Original.
PLATE 43.
Fig. 1-—Vertical section of a tooth of
Microdon radiatus magnified 50 linear
diameters. Fig. 2. A section, in the
direction indicated by the lines, of an
incisor of Sargus rufescens: a, dentine;
b, modified enamel: c, clear intermediate
space (calcified preformative membrane) ;
d, osteo-dentine. Original.
PLATE 44.
Fig. 1.—Four of the premandibular teeth
of the Acanthurus nigricans magnified
30 linear diameters : a reduced view.
Original. Fig. 2. A vertical longitudinal
section of the continuous parts of four
of the. lamelliform teeth of the Phyllodus
toliapicus: a, the osseous basis; b, the
dentine; e, the enamel. Original. Fig. 3.
Two of the teeth of a Chatodon: a, front
view of the subtransparent tooth ; b, side .
view of the longitudinal section, showing
the pulp-cavity (v. Bom)*. Fig. 4. A vertical
section of the right intermaxillary
bone of the Chrysophrys: a, the posterior
oval triturating dental plate ; b, the germ
of its successor in the alveolus of reserve;
c, the rudiment of the third generation of
the same tooth; the line from letter b
shows the tract of communication, still
open, between the second and third alveolus.
(Cuvier and Val.) Fig. 5. The
tooth of a Pike in progress of formation,
with its capsule and a portion of the surrounding
gum: a, the apex of the calcified
tooth; b, the external membrane of the
gum reflected around the base of the
* Heusinger’s Zeitschrlft, Bd. i. 1827.
tooth to form its capsule; c, the dentinal
pulp ; d, the nerve of the pulp (v. Born) ;
Fig. 4. The right premandibular bone of
a young Pike, dissected to show the
nerves of the tooth, viewed from the inner
side: a, branches of the third division of
the fifth pair of nerves; b, branchlets of
the same to the integuments on the outside
of the jaw ; c, twigs for the teeth ;
one is sent off to each tooth; d, branch
which perforates the bone, supplies that
part and the outer integuments, (v. Born.)
PLATE 45.
Fig 1.—Inside view of the intermaxillary
bone and teeth of a Wrasse (La-
brus, Linn., Cossyphus, Cuv.) Fig. 2.
Inside view of premandibular bone and
teeth of ditto. Fig. 3. Pharyngeal bone
and teeth of the southern Gilt-Head,
(Chrysophrys australis). Fig. 4. The
two upper pharyngeal bones and teeth of
a large species of Wrasse (Labrus).
Fig. 5. Pharyngeal bone and teeth of
Chrysophrys aurata. Fig. 6. A vertical
section of a pharyngeal tooth of a Chrysophrys,
Original.
PLATE 46.
Fig. 1.—A vertical section of a pharyngeal
bone and teeth of a Labrus: a, teeth
in use; b, successional teeth. Fig. 2.
A magnified view of a similar section
of a single tooth and its socket of a Z,a-
brus. Original.
PLATE 47.
Fig. 1.—Upper surface of the dental plate
of an extinct Ganoid Fish (Phyllodus).
Fig. 2. Under surface of the same.
Fig. 3. Upper surface of a median dentigerous
bone of the Pisodus Owenii. Ag.
Original.