DEVELOPMENT OP THE SKULL IN THE BATRACHIA. 
20 ?) 
In the orbital region the endocranium forms scarcely more than a third of the 
expanse ; the rest is due to the roof bones (fi-P-) ; they increase in size from before, 
backwards ; the cranial box, from behind, forwards. Behind, the endocranium is 
exposed very little ; the edge of the occipital ring is bare, and so are the epiotic 
eminences, and the bony ear-capsules for a small space further outwards, and forwards. 
The paroccipital wings, ending in the “ tegmina,” are very much outspread, but they 
are roofed over and hidden by the huge top of the squamosals (sep). 
The endocranium is not wanting in height (fig. 3), its ethmoidal axil he are large 
and shallow (fig. 2, eth.). The snout is very broad, but rounded ; it is unusually steep 
(fig. 3). The winged portion of the girdle-bone is largely hidden, below, by the 
enormous palatine bones (fig. 2, etli., pa.). The subnasal laminae (fig. 2) are wide, 
and are half occupied by the extended ossification of the ethmoid. Above, the nasals 
hide all but the end of the snout (fig. 1, n.) ; when these are removed it is seen that 
the roof-cartilages (n.r.) merely form a widish ring round each outer nostril (e.n.), and 
perhaps run a little along the side of the septum (fig. l). These rimmed nostrils are 
large and wide apart, and the second labial (u.l' 2 .) forms a very large valve in front of 
the passage. The first labial (u.l 1 .) is small and lenticular ; it supports the first, lying- 
inside the rod-shaped vertical nasal process of the premaxillary (fig. 3, n.px.). 
The roof cartilage swells (fig. 1) out on each side of the bevelled end of the septum; 
below (fig. 2, p.rh.), the pro-rhinals are seen as inbent-spikes. The cartilage of the 
palatine and pterygoid regions is broken up into an etlimo-palatine and a pterygoid, 
the bones corresponding to these regions having devoured most of this sub-ocular 
arch. 
The palatine bones (fig. 2, pa.), together, form a strong cross-bar, as thick and 
almost as long as the mandible (fig. 3). They are sigmoid, flattened within, where they 
meet and form a strong suture; they are dilated and convex, and, externally, become 
falcate. A bony ridge, sub-distinct, and half their length, grows from their middle— 
at an equal distance from each end; it is sharply serrated, and the serrce (fig. 7, pa.,pa .) 
might easily be mistaken for teeth ; they are undoubtedly the atavistic marks of teeth. 
The hooked end of the palatine slightly overlaps the corresponding pterygoid (pg.) ; 
this latter is an extraordinary bone, composed of three nearly equal rays, each of 
which strongly clamps the contiguous parts of the skull. 
A small epipterygoidean rod of cartilage still lingers in the outer part of the front 
ray (fig. 3, pg., up.) ; this runs to a point in the fixed, bony pedicle ( pd. ) ; below, it 
widens, and then is stopped by the bony growth of the quadrate ( q .), borrowed from 
the quadrato-jugal (<]■]■)■ 
A rounded angle, less than a right angle, lies between the jugal part of the ptery¬ 
goid and the bony pedicle (pd.). The former bar becomes a style in front, being 
aborted by the huge maxillary (mx. ) ; it swells outwards against the space for the 
temporal muscle, and then becomes vertical, applying itself to the inner face of the 
quadrate, as it descends, growing also both backwards and outwards. The inner ray 
2 d 2 
