lars. Fig. 2. Upper and lower molars, I
right side, of the nine-banded Armadillo
(Tatusia Peba). Fig. 3. Ditto of the
Weasel-headed Armadillo (Dasypus 6-
cinctns). F. Cuvier. Fig. 4. Longitudinal
section of the tooth of Dasypus 6-cinc-
tus). Magnified 300 linear diameters ; a,
osteo-dentine ; b, b, hard dentine; c,
cement. Original.
PLATE 86.
Fig. 1.—Portion of a molar tooth of the
gigantic extinct Armadillo (Glyptodon
clavipes). Fig. 2. Grinding surface of
ditto. Fig. 3, Part of magnified section
of ditto; a, osteo-dentine; b, b, hard
dentine; c, cement. Fig. 4. Transverse
section of upper molar of Toxodon platen-
sis ; § nat. size. Fig. 5. Ditto of lower
molar of Toxodon. (The enamel is erroneously
drawn as extended over the whole
concave folded side of the tooth). Original.
PLATE 87.
Fig. 1. Reduced view of base of skull, with
the hidden rudimental tusk, and the base
of the long tusk of the male Narwhal.
(The mirror not having been used, this
tusk is figured in the right, instead of the
left intermaxillary). Fig. 2. Base of
skull of female Narwhal, with both the
rudimental tusks exposed. Fig. 3. Edentulous
lower jaw of the Narwhal. Fig.
4. Section of large tusk of the male.
Home.
PLATE 87 a.
Fig. 1. Rudimental teeth in the alveolar
groove of the upper jaw of the fetal Ba-
Uenoptera Boops. Fig. 2 to 6. Teeth
from the same of the natural size. Eschricht.
Fig. 7. Lower jaw and teeth of
the Gangetic Dolphin (Platanista gange-
ticd); a and b, detached teeth, nat. size.
Home.
PLATE 88;
Fig. 1. End of the upper jaw of a young
Hyperoodon bidens, shewing,the two teeth.
Fig. 2. Part of the lower jaw of a Dolphin
([Delphims Delphis) ; with the roots
of the teeth exposed. Original.
PLATE 89.
Fig. 1. Reduced view of the lower jaw and
teeth of a Cachalot or Sperm-whale (Phy-
seter macrocephalus). Fig. 2. Section of
a tooth of ditto, j nat. size; a, cement;
b, dentine; c, osteo-dentine. Fig. 3.
One of the concealed teeth of the upper
jaw; nat. size. 4. Fore part of its pointed
end. Original.
PLATE 89 A.
Fig. 1.—Part of longitudinal section of the
teeth of a Cachalot, magnified 230 linear
diameters. Fig. 2. A peripheral portion
of ditto, magnified 500 linear diameters;
а, b, dentine; c, cement. Original.
PLATE 90.
Fig. 1.—Inside view of left ramus, lower
jaw, of Diprotodon australis, -Jth nat.
size ; i, outline of incisive tu sk ; m, 1 to
5, molar teeth. Fig. 2. Outline of transverse
section of crown of incisor, shewing
partial covering of enamel. Fig. 3. Crown
of penultimate molar; m, 4, nat. size.
Fig. 4. Inside view of left ramus, lower
jaw of Nototherium inerme, |t h nat. size;
m, 1 to 4 ; outlines of molar teeth. Fig.
5. Crown of penultimate molar of Tapi-
rus americanus, nat. size. Original. Fig.
б. Upper and lower jaw of Mastodon angustidens,
|th nat. size, i, i. Outlines of
lower and of base of upper incisive tusks;
; m> 6 and m, 7, penultimate and last mo-
■ lar teeth. Kaup.
PLATE 91.
fjfig. 1.—Transverse section of crown of
I molar of Zeuglodon ceto'ides; a, isth-
I mus connecting the two lobes. Fig. 2.
I Magnified view of portion of transverse
I section of the same; a, central osteo-
I dentine; b b, unvascular dentine, showing
1 contour lines of basal substance ; c, ce-
I ment. Fig. 3. Small portion of outer
| part of previous section more highly
| magnified, showing ƒ, indications of den-
E tihal cells, secondary branches, and e,
I terminations of dentinal'tubes ; d, cellular
j and fine tubed cement. Original.
PLATE 92.
A section of the upper jaw of a young Dull
gong, (Halicore indicus) showing all the
K teeth that are developed in that jaw in
K situ; § nat. size : a, deciduous incisor;
I: b, permanent incisor, in longitudinal sec-
■ tion; c, first molar; d, second molar
K e, third molar: these three molars are
1 deciduous, but are not replaced by suc-
■ cessors : ƒ, fourth molar; g, fifth molar.
I 'These two molars are persistent and cha-
!< racterize the adult Dugong. Original.
PLATE 93.
WlrJ' 1'—Base view of upper jaw of Dugong,
I 2 nat. size; e, remains of third or ante-
I penultimate molar; f , penultimate molar;
| g, last molar. Fig. 2. Upper view of
I left ramus of ■ lower jaw, £ nat. size ;. a,
1 abortive incisor in one of the sockets of
| the deflected symphysis: e, antepenulti-
1 mate molar; f , penultimate molar; g,
last molar. Behind this is exposed a
cavity in the substance of the jaw ; not
an alveolus. Fig. 3. Abortive incisor
of the lower jaw, nat. size : a, contracted
base, or pulp-cavity ; b, crown wasted by
the absorbent process. Fig. 4. Section
of incisive tusk of male; ^ nat. size. Fig. 5.
Side view of antepenultimate molar, nat.
size. Fig. 6. Crown of last upper molar,
nat. size. The clear outer border shows the
thickness of the cement. Home.
PLATE 94.
Reduced figure of a magnified view of a
transverse section of the penultimate
molar of a Dugong, showing the thick
border of cement; the cells of the dentine
near that border ; the course of the dentinal
tubes, and the central osteo-dentine.
* Nat. size. ^ Original.
PLATE 95.
Fig. 1.—Magnified view of a section of the
incisive tusk; c, the cement, with radiated
cells ; e, the enamel, d, the
dentine, showing the course and terminations
of the tubes, and the peripheral
outlines of the dentinal cells. Fig. 2.
Magnified view of part of a transverse
section of the same tusk : a, transverse
sections of tein tercellular dentinal tubes;
b, clear outlines of the dentinal cells.
Original.
PLATE 96.
Fig. 1.—Side view of upper molars of
Manatee (Manatus americanus): a, incisor,
| nat. size. Fig. 2. Grinding
surface of upper molars. Fig. 3. Side
view of a lower molar, nat. size. Fig. 4.
Teeth of Tapirus americanus : the dotted
lines divide the premolars from the true
molars, f nat. size. Fig. 5. Grinding
surface of lower molars. Fr. Cuvier.
Fig. 6.—Lower jaw and part of upper