DEVELOPMENT OE THE SKULL IN THE BATRACHIA. 
47 
Above (fig. 1), and below (fig. 2), we can trace here and there some remains of the 
cartilage; above, in the ethmo-palatine, the pre-palatine, and the post-palatine, on the 
supero-external edge of the pterygoid ; below, on the end of the “ pedicle,” its articular 
facet; and above and below the graft of the quadrato-jugal; the latter being the 
coating of the large bilobate hinge (q.c.). 
These inner works of the skull, so largely converted into solid bone, are built over 
by very strong membrane-bones, which give the finish and the beauty to this style of 
cranial architecture. 
Below, in relation to the skull proper, the parasphenoid (fig. 2, pa.s .) is of the usual 
relative size, but looks small as compared with the large bones of the face ; it is typical 
in form, but unusually strong. 
The vomers (fig. 2, v.) here attain a very large relative and real size, for they meet at 
the mid-line (compare them with those of R. gracilis, fig. 7, v.) ; their snags are large 
and strong, and the oblique dentigerous lobe of each is of considerable extent. 
Above, the fronto-parietals (fig. 1 ,fp.) form a strong roof with a notch in front, the 
remains of the frontal suture, but are wholly coalesced beyond this ; they end, behind, 
in two broad wings which spread over the hinder region of the cranium, almost to 
the end. At first, hollow in the middle, in the postorbital region they develop a 
sagittal crest, which opens out into two temporal wings. The temporal part dips 
into the orbit (fig. 3, f.p.) and then rises over the ear-masses, moulding itself on to 
their sinuosities. The sides are notched, and the end has a concave margin. 
The nasals in front (figs. 1 and 3, n.) form cross bars which are nearly as straight 
as the wings of the parasphenoid; they meet along the middle, run their pointed ends 
far forward, are triangular behind, where they overlap the fronto-parietals, and with 
them cover the girdle-bone—all but the superorbital projections and the middle part 
in front of the fontanelle. The fontanelles are presumably like those of the lesser 
kinds, but they are quite covered over. 
The investing bones, outside, differ from the type in relative size and density; other¬ 
wise they are quite normal: there is no septo-maxillary, the palatal ingrowths are well 
developed, the nasal process of the premaxillaries and of the maxillaries (px ., mx .) 
is strong; the quadrato-jugal (q.j.) is grafted on to the quadrate, and the three regions 
of the squamosal (sq.) are extremely well developed and give the highest idea of the 
Batracliian form of these bones. So, also, the various condyles—of the occiput, the 
pedicle, and the mandible—are well and typically formed. The mandible (fig. 3) is 
crested both in its dentary and coronoid regions. 
The stapes and its additions are of an average size (figs. 3 and 5) ; the stapes (st.) 
has its fore margin oblique ; jammed in between it and the fenestra! edge of the 
capsule there is the large seed-like inter-stapedial (i.st.); then, distinct from it, the 
pistol-shaped medio-stapedial ( m.st .), whose unossified part passes into the broad 
spatula of the extra-stapedial ( e.st .), which sends upwards its supra-stapedial (s.st.) ; 
this is hgulate, and confluent above. The stylo-hyal end of the hyoid tape is 
