PISCES. 
Seeing, therefore, that the teeth of Fishes are 
derivations from pulps formed by the mucous 
lining of the mouth, it can be a matter of small 
astonishment to find that they can be developed 
‘mm any part of the oral cavity where the 
necessities of a given species may require 
their presence, without relation to the jaws, 
with which alone they are connected in the 
nates races of Vertebrata and in the human 
su 
Accordingly in the class under consideration 
teeth are found attached to any or all of the 
following parts of the mouth and of the pha- 
Fynx, viz. to the superior and inferior maxilla, 
to the intermaxillary bones, to the palate bones, 
to the vomer, to the tongue, to the branchial 
arches, and to the superior and inferior pharyn- 
geal bones. The ichthyologist is therefore com- 
pelled to designate the different parts of the 
dental system according to the bones or other 
Structures whereon they are situated, and distin- 
guishes intermaxillary teeth, maxillary teeth, 
mandibular teeth, vomerian teeth, palatine teeth, 
pterygoid teeth, lingual teeth, branchial teeth, 
superior pharyngeal teeth, and inferior pha- 
ryngeal teeth, all of which may sometimes be 
coexistent, rendering the teeth of Fishes prodi- 
giously numerous. As relates to their form 
the dental organs offer a far greater number of 
varieties than those of other vertebrate animals. 
Sometimes they are so minute as only to be 
perceptible by the rough or scabrous surface 
which the parts of the mouth to which they are 
attached present. If of larger size, they pre- 
sent the appearance of a file or rasp (dents en 
rape), or they may have the shape of small 
cones or hooks thickly scattered over the pa- 
rietes of the mouth. Sometimes they are so 
fine and slender as to resemble the pile of 
velvet (denis en velours ), or elongated, having 
the ce of fine bristles. In Citharina 
these bristle-shaped teeth are bifurcated to- 
wards their free extremities, or they may termi- 
nate in three diverging points, as in the anterior 
teeth of the genus Platax. Or the elongated 
cone may be compressed into a slender tren- 
chant plate, and this may be pointed, recurved, 
or even barbed like a fish-hook, as is the case 
an Trichiurus and some other Scomberoid 
Fishes; or it may be bent upon itself like a 
VOL. III. 
977 
tenter hook, as in Pemelepterus and Go- 
niodontes. Sometimes the dental cones 
present a thickened base, giving them the 
appearance of the laniary teeth of carni- 
vorous quadrupeds, as is the case with 
the large teeth of the Pike ; or they may 
be flattened into broad plates of hemi- 
spherical or other shapes, constituting a 
crushing apparatus adapted to bruise the 
food 
A thin lamella, slightly concave like a 
finger nail, is the singular form of the 
tooth of an extinct species of cartilaginous 
fish named by Professor Owen Petalo- 
dus.* Sometimes each tooth presents a 
flattened incisor crown deeply notched in 
the middle of the cutting edge, as in 
Sargus unmaculatus. Sometimes there is 
a double notch, rendering the margin of 
the tooth trilobate, as in Aplodactylus; or it 
may be divided into five lobes by a double 
notch on each side of the central and largest 
lobe, as in Boops. 
In the great Barracuda pike (Sphyrenc ) the 
crown of both the large and small lamelliform 
teeth is prolonged into a sharp point, closely 
resembling a lancet. A similarly shaped pier- 
cing and cutting tooth is in many of the Sharks 
furnished with one or more accessory cusps at 
its base, and the cutting margins of the tooth 
are frequently notched, serrated, or crenated. 
Prismatic teeth with three sides are fixed to the 
jaws of Myletes ; and in some instances, as in 
Scarus, they assume the shape of four-sided 
prisms. 
The teeth of Fishest present greater diversity 
in their mode as well as in their place of attach- 
ment than is observable in any other class of 
animals. In a few instances they are im- 
planted in sockets, to which they are attached 
only by the surrounding soft parts, as, e. g. 
the rostral teeth of the Saw-fish (Pristis). 
Some have their hollow base supported, like 
the claws of the feline tribes, upon bony pro- 
minences which rise from the base of the 
socket; the incisors of the File-fish ( Balistes ) 
afford this curious example of a double gom- 
phosis, the jaw and the tooth reciprocally 
receiving and being received by each other. 
The teeth of Sphyrena, Acanthurus, Dic- 
tyodus, &c. are examples of the ordinary im- 
plantation in sockets with the addition of a 
slight anchylosis between the base of the fully 
formed tooth and the parietes of the alveolar 
cavity. But by far the most common mode of 
attachment of fully formed teeth is by a con- 
tinuous ossification between the dental substance 
and the jaw, the transition being gradual from 
the dental to the osseous tissue. The tooth 
prior to its anchylosis is connected by ligamen- 
tous substance, either to a plain surface, an 
eminence, or a shallow depression in the bone. 
Sometimes not the end, but one side of the 
base of the tooth is attached by anchylosis to 
the alveolar border of the jaw; it might be 
supposed that in this case the crowns of the 
* Owen, Odontography, p. 2. 
¢ Owen, loc. cit. 
328 
