TRACHINOIDS.
59. The dental system of the fishes of the family of Trachinoids
offers few particulars deserving attention : and I shall briefly allude
to the modifications which are exemplified in two of the genera referable
to this group.
In the Weevers (Trachini Draco, et Vipera) the intermaxillary,
premandibular, palatine, vomerine and pharyngeal bones are beset
with minute villiform teeth: they are arranged in two longitudinal
hands upon the palatines, and form a single transverse band in front
of the vomer. The tongue is edentulous.
In the Star-gazer, (Uranoscopus scaber), an exotic species of
Trachinoid fishes, the intermaxillaries, pharyngeals and vomer, have
their masticatory surfaces roughened like a rasp by numerous small,
hut more strongly developed teeth: those on the palatines are still
larger: and the premandibulars support eleven strong canines
separated by intervals, and placed behind a small patch of villiform
teeth near the symphysis. -
In microscopic structure and mode of reproduction the teeth
of the Weevers resemble those of the Pike.
LOPHIOIDS.
60. In this singular family of fishes in which the pectoral fins are
developed into terrestrial locomotive organs, the peculiarities of the
dental system will he principally illustrated by a description of the
teeth of one of the largest species, which is at the same time a native
of our own coasts.
The Angler, (Lophiuspiscdlovius), has teeth on the intermaxillary,
premandibular, palatine, vomerine, and pharyngeal bones. They are
of an elongated, conical, sharp-pointed, and slightly incurved form,
presenting merely differences of size, degree of curvature, and mode
of fixation, hut all bespeaking the predatory and carnivorous habits of
the species.
In the upper jaw, the teeth are congregated in three or four ir-
regular rows at the median or upper third part of each intermaxillary
bone, and form a single and regular series along the lower two-thirds.
These latter, which may be termed the serial teeth, are from fifteen
to eighteen in number, short, strong, pointed and incurved ; of nearly
equal size and placed at regular distances from each other. (1) The
two outer irregular rows of the median intermaxillary teeth are
somewhat larger and are directed forwards ; the inner rows at this
part contain the longest teeth and their points are turned back ; but
they are moveably connected with the hone by a mechanism which
will be described when treating of those of the lower jaw.
The premandibular teeth can hardly be said to form a regular
series, but are scattered along the alveolar margin of the lower jaw
in an irregular quincuncial disposition ; being three, four, and five
deep towards the middle and anterior part of the lower jaw, in full
grown specimens. The largest teeth in the mouth of the Lophius
are the innermost and median ones of the premandibular bones ; they
decrease in size as they are situated more laterally. The transverse
section of the body of these laniariform teeth is nearly circular, but
at their broad and expanded base it is triangular with one of the angles
directed outwards. The palatine teeth form a single row, near the
outer edge of the bones, the median ones being the largest; the
cluster of two or three teeth on each side of the expanded anterior
extremity of the vomer seem to terminate the palatine series.
The superior pharyngeal teeth are arranged in three groups upon
as many separate bones on each side; each group describes a curve
with the convexity turned forwards ; the teeth of the posterior bone
are the smallest. The inferior pharyngeal bones are two in number,
and have the teeth arranged in a double alternate row along each
margin.
The pharyngeal, palatine, and vomerine teeth are fixed by anchylosis
to their respective bones ; this is also the case with most of
the intermaxillary teeth, and with the exterior teeth of the lower jaw;
but the remainder, and especially the large posterior fangs of the
lower jaw, are attached by means of elastic ligaments to the margins
of slightly elevated alveolar processes. These ligaments are prin-
(I) In the Lophius Upsicephalus the corresponding serial intermaxillary teeth are described
as being short, delicate and cylindrical, by Dr. A. Smith in his excellent “ Zoology of South
Africa.”