seven molars on each side the upper jaw, and a tail as long as
the body; it inhabits Cayenne and the northern parts of Brazil.
The Das. septem-dmtus. L., (D. hybridus, Desm.)(l) has likewise
seven molars on each side of the upper jaw, and a tail much shorter
than the body.
The Armadillos of the suhgenus Euphractus, Wagler, to which
the term Dasypus is restricted by F. Cuvier, are distinguished by
having the anterior tooth, which is shaped like the succeeding
molar, implanted in the maxillary hone. The species of which the
dentition is figured by. M. F. Cuvier(2), is the Dasypus sex-dnctus of
Linnaeus, the Weasel-headed Armadillo of Grew. It has ifEfo = 38
teeth. Those of the upper jaw gradually increase in size to the
sixth, and diminish from the seventh to the ninth : they present
an elliptical, transverse section, which is narrowest in the small
anterior teeth. The two anterior teeth of the lower jaw being in
advance of the intermaxillary tooth, are, with it, arbitrarily held
to be incisors : they are compressed, but are terminated by obtuse
crowns: the rest of the series, from which the incisors are not
separated by any remarkable interval, gradually increase in size
to the penultimate molar: they have the same alternate position
and obliquely worn grinding surfaces as in the Tatusias.
Among the extinct species, that forming the type of the genus
called by M. Lund Euryodon is distinguished from all existing Armadillos
by having the teeth compressed from before backwards, instead
of laterally; but the grinding surface consists, as usual, of
two facets, which meet at a more or less acute angle in a transverse
ridge (3).
In a second extinct genus, Heterodon, Lund, the teeth exhibit
much less conformity in shape and size than in the existing Armadillos.
Both the anterior and posterior molars are small and
conical ; while the penultimate and ante-penultimate are much
larger, the former being oval, the latter heart-shaped in transverse
section.
(1) This species occurs only in the extra-tropical part of S. America,
(2) Loc. cit. PI. lxxix.
(31 Blik paa Brasiliens Dyreverden For Sidste Jordomvteltning, af Dr. Lund, Kjobenhavn,
•lto. p. 1.
In the Chlamydotherium, Lund, there are eight teeth on each
side of the upper, and nine on each side of the lower jaw : of
these the two anterior ones in the upper jaw, and the three anterior
ones in the lower jaw, are incisors by position. The latter are
shaped like small cylinders, with a more or less reniform transverse
section, while the molars are very large and compressed, so that
their section resembles an elongated kidney: their sides are marked
with several canaliculate impressions, and their grinding surface
presents two projections, the effect of the action of the teeth of
the opposite jaw ; elsewhere the surface is flat, and a little hollowed
in the middle. The size of the species (Chlarn. Humboldtii), of which
the dentition is here desoribed, was six feet, or double that of the
Priodon, which is the largest of existing Armadillos; but the Chlam.
giganteum equalled in bulk the Rhinoceros.
The extinct Glyptodon( 1) seems to have surpassed the Rhinoceros
in size: and its dentition(2) was more complicated, more adapted to
a vegetable diet, than that of the Chlamydothere. The total number
of teeth in the Glyptodon has not yet been determined. A
fragment of the anterior part of the lower jaw shows that the teeth
extended close to the symphysis, and, therefore, indicates their
presence in the intermaxillary hones above. The single tooth, on
which the generic character of the Glyptodon was founded, is long,
rootless, as in the existing Armadillos, hut compressed laterally,
and divided by two deep, angular, longitudinal, and opposite grooves
on each side, into three plates, which give the grinding surface
the form of as many rhomboidal lobes. The alveoli on the fragment
of jaw above mentioned, indicate the anterior teeth there to
have had the same form, and, from the allusion which Dr. Lund(3)
makes to the teeth in the Hoplophorus (Glyptodon) of the Brazilian
Caverns, it would seem that the complicated form just described,
pervaded the whole dental series.
The teeth of the Armadillo-tribe are harder than those of
(1) SirW. Parish’s Buenos Ayres, 8vo. 1839, Geol. Trans. 2nd series, vol. vi. p. 81—85.
(2) PI. 86. fig. 1 and 2.
(3) “ Its teeth are shaped like the molars of the Capibara, but have a different structure,
inasmuch as they are simple, and not composed of laminae.” Loc. cit. p. 10.
Y 2