xo 
BULLETIN OF THE LABORATORIES 
this process, which descends below the level of the jugal, a nearly ver- 
tical plate extends upward to form a sliding sheath which clasps the 
presphenoid and plays back and forward upon it. The flattened ends 
of the long (.50) pterygoids are fused with these vertical plates by ex- 
panded, overlapping plates. There are two curved flanges springing 
from the point where the pterygoids unite with the palatals. The eth- 
mo-turbinal plates are more or less ossified and are seen on either side 
of the rudiment of the vomer. The pterygoids are stout but very 
unusually long and, on account of the size and position of the quad- 
rate bones, are quite distant from the basis cranii. Near the point of 
union of the pterygoid with the quadrate bone, a small hooked process, 
about . 12 long, extends upward from the former bone. What the use 
or the homologies of these processes may be, we do not know, although 
they occur in finches and in other birds. 
At the posterior of the two mandiblar processes of the quadrate 
bone is a bone as large as the head of a large pin, but of irregular 
shape, which may be regarded as either a sesamoid contributing to lock 
the jaw or an independent portion of the quadrate. There is also a 
very minute sesamoid at the union of the quadrato-jugal and the quad- 
rate. The lower jaw shows no evidence of its composite character. 
The whole anterior half is enlarged and forms a simple trough of can- 
cellous bone which may be assumed to consist of the dentary elements 
of both rami. The surangular, angular and splenial elements of the 
rami are not distinguishable. The articular portion consists of a huge 
flange, extending inward and upward and is perforated at the middle of 
its inner surface for the entrance of Meckel’s cartilage. 
What corresponds to the surangular portion is a broad triangular 
plate extending upward inside the jugal bones and serving to further 
lock the jaw. Thus, as we have seen, the whole skull is modified in 
harmony with the enormous rhinencephalic development. 
The hyoid arch is well developed and consists of seven bones, 
whose homologies, in the present state of our knowledge, cannot be 
made out. The anterior pair are pointed before and behind and at- 
tached at the middle to each other and the end of the azygos bone 
which next follows. The first mentioned bones are called entoglossal , 
by Gegenbaur, by some American authors, ceratohyals , with no real 
evidence that they are homologous with the bones so called in other ani- 
mals, The following element may be called basihyal ( copula of 
Gegenbauer,) and is flattened to form a vertical plate and bears on 
OF DENISON UNIVERSITY. 
1 1 
either side, posteriorly, the cornua, which each consists of one straight 
shaft, .50 long, and a shorter fusiform segment. Between these the 
urohyal extends backward as a support to the trachea. The atlas 
and axis are fused together more or less fully. There is no neural 
spine on the atlas, but its dorsal surface is perfectly plane. The axis, 
or second cervical vertebra, has a well developed spine and posterior 
zygapophyses and also a very large haemal spine, which curves back- 
ward. The third cervical has a smaller neural spine and its poste- 
rior zygapophyses project upward. Its haemal spine ( hypapophysis) 
curves forward. There is a slight inferior lamella of its transverse 
process. The fourth cervical introduces a new type, having a low 
spine, nearly horizontal posterior zygapophyses, and elongated styloid 
inferior lamellae. It has a smaller haemal spine. The following cer^ 
vicals have no neural or haemal spines, the posterior zygapophyses de- 
cline, and the styloid appendages are very long. The thirteenth and 
fourteenth (last) cervicals have pleuropophyses (ribs), those of the 
former being mere rudiments, while those of the latter are large but 
have no connection with the sternum. These vertebrae, in common 
with the first of the dorsals, have strong haemal spines. They also 
have the capitula process well developed to receive the head of the 
rib. The transverse process has its normal tubercular facet to sus- 
tain the tubercle of the rib. There are six dorsal vertebrce, which 
are more or less firmly co-ossified. The transverse processes are 
large and the spines of uniform size. The last dorsal is firmly united 
with the following nine vertebrae, which form the vertebral framework 
of the sacrum. Seven free vertebrae follow, forming the free caudal 
series. Each of these has a strong transverse process and a more or 
less perfect neural spine. Upon the last two there are also haemal 
spines. The last bone or pygostyle is remarkable for the great devel- 
opment of its neural spine. 
The sternum is normal for the group and is 1.20 inches long. The 
keel is well- developed, being .50 high. The mid-xiphoid process is 
.40 wide at the end. The lateral xiphoids are separated by an excis- 
ion one half as wide and rather more than .40 deep. The transverse 
sternal angle (that between the two sides of the body of the sternum,) 
is sharp and considerable. The costal processes are strong, while the 
coracoid grooves are .25 in width. The manubrium is particularly 
large and is bifid. Each of the six ribs, as well as the last cervi- 
cal rib, has a well developed uncinate process. 
