DEVELOPMENT OF THE SKULL IN THE BATRACHIA. 
113 
much less typical, and some of them are very aberrant and generalised. Hence it 
comes to pass that this is rather a motley group, and the question arises as to whether 
it should not be broken up and redistributed; if this were done the boundaries of the 
groups that should receive their own relations back again, would have to be made 
more elastic. This type would have to go to the Ranidse ; Calyptocephalus to the 
Cystignatliidse ; Pelodytes would ask for admittance, either among the Bombinatoridse, 
or the Alytidee ; whilst Xenophrys, and the kinds agreeing with it, would probably 
have to be made into a new family; that species is exceedingly generalised, and shows 
affinity with families far removed from the Ban kite, far more clearly than with those 
typical Frogs. My mention of these things is as a protest against the family group 
as it now stands : the Zoologists must re-arrange it as they see fit. 
As far as the skull is concerned, this type might have been left in the genus Rana, 
or still better, put with the species of Pyxicephalus ; with that of P. rufescens it agrees 
very closely. This is a typical semi-elliptical skull, whose breadth is to the length as 
15 to 14 ; it is more frail, or less ossified, than in the average Frog’s skull; and its roof 
is imperfectly covered. 
The extent of the three regions of the skull is normal, the orbital being the largest, 
the nasal next, and the auditory the shortest. The occipital condyles (Plate 20, 
figs. 7, 8, oc.c.) are large, semi-oval, almost directly posterior, and separated by a 
narrow notch. 
The epiotic projections ( p.sx .) are gently convex, and come short, behind, of the 
condyles. The quadrate hinges are opposite the large twin nerve-passage ( q.c ., IX. X.). 
The small ex-occipitals ( e.o .) are wide apart both above and below, and are at a con¬ 
siderable distance from the equally arrested prootics ( pr.o .); these latter bones enclose 
the foramina ovalia (V.), run out to the facet for the pedicle ( pd .), and up over the 
anterior canal (a.s.cf Beyond these bones the tegminal region (fig. 7) is only half the 
width of the canal region, and runs only a moderate distance beyond the horizontal 
canal ( h.s.c .). The skull is well roofed, for the main fontanelle (fo.) is a rather small, 
long, heart-shaped space, and the small secondary fontanelles are wide apart on the 
large hinder part of the tegmen cranii. 
The temporal region is wide, and from thence the orbital part of the skull narrows 
up to the rudimentary superorbital projections (s.ob.); these increase the width a little in 
the ethmoidal region, but, as in Pyxicephalus rufescens (Plate 14, figs. 1, 2), the cranial 
boat is very constricted in front. As in some small Ranidse from Australia ( e.g ., 
Camariolius), the girdle-bone (eth.) is imperfect; it occupies only about a fourth of the 
interorbital region at its widest; its halves are united by a narrow isthmus below, and 
scarcely meet above. 
Most of the ethmoidal region, with its wings, and all the wide, well-developed, 
normal nasal region, are cartilaginous. Both roof and floor (figs. 7, 8) are wide, 
the septum (s.n.) is high and thick, the snout gently convex, with a slight prenasal 
bud; and the pro-rhinals ( p.rh .) and subnasal outer angles are large and well 
MDCCCLX XXI. Q 
