Freiburger historische Bestände - digital

EXPLANATION

OF

PLATE 32.

In the three figures 1—3 most of the zygoma has been taken away.

Fig. 1. Skull of a young Ursus, from the right, {. In the orbit are seen an ethmoidal foramen, the optical
foramen and the orbital fissure, lying in a common furrow. Behind the anterior rest of the zygoma is seen
the large processus of the maxillary, containing the germ of m2.

Fig. 2. Skull of an old Ursus maritimus, \. In this the furrow containing the three foramina has become
much more marked, the upper border of it having been developed as a sharp rim. The large processus from
the maxillary figured in fig. 1 has been reduced to a small thin protuberance (is seen below the anterior end
of the zygoma),

Fig. 3. Right half of the skull of the Elephant Chang. Compare it with fig. 2. The furrow containing the
foramina has been so deepened that they cannot be seen without the rim being broken off. Notice also the
very different way in which the great surface behaves, from which the m. temporalis arises in both: in the
Bear it extends from the rim unto the posterior end of the skull, which has a large longitudinal extension
much exceeding the height, the said surface extending far beyond the posterior root of the zygoma while in
the old Elephant it does not go further back than the zygoma, the longitudinal extension being much inferior
to the vertical extension and the surface building a deep groove on the side of the skull. Another remarkable
difference is that the part of the skull lying below the zygoma is quite low in the Bear, while it is high in
the Elephant, etc.

frontale

parietale

nasoturbinal
ethmoid
lacrymale
nasale

entrance to maxillary sinus

maxilloturbinal basal plate

margin of horizontal plate of maxilloturb.
(the spiral laminae taken away)

maxilloturbinal basal plate

ethmoid

suture between
pre- and basi-
sphenoid
alisphenoid
| pterygoid

| lamina transversa
palatine

bramen sphenopalatinum

supraoccipitale

Fig. 4. Median sec lion
of the skull of a Lamb half
a year old, to show the basal
plate of the maxilloturbinal,
the turbinate part of which
has been taken awav. The
anterior part of the nasoturbinal
and of the ethmo-
turbinals have been cut off. \.

entrance to sinus intermaxil-
laris inf.

entrance to sinus maxillaris

parietale

closed suture of parietal and supraoccip.

supraoccipitale

frontale

nasoturbinal

nasale

perpendicular plate in the groove
for the lig. nucha;

squamosum

exoccipitale

intermaxillare

ethmoid

basioccipilale
tympanicum
petrosum

tympanicum
basisphenoid

alisphenoid
suture betw. pre- and basisphenoid
rest of vomer (the greater part taken away)

lamina transv. palatine

Fig. 5. Median section
of the skull of the Elephant
d. The broken line on the
supraoccipital designs the
contour which this bone
would have had, if the thin
perpendicular bony plate in
the nuchal groove had been
removed, c. \.

Fig. 6. Right intermaxillary
, maxillary and
maxilloturbinal
, isolated
from the rest,
of the skull b,
seen from the
medial side.
For better understanding
the figure an outline of
the maxilloturbinal is placed
here.