DEVELOPMENT OF THE SKULL IN THE BATRACHIA. 
115 
this respect it is intermediate between that of Pleurodema and Lymnodynastes, types 
to which it can claim no near relationship.* 
But there are two European Frogs to which this type has some claims of relationship; 
these, Bombinator and Alytes, however, are very exceptional forms, having “opisthocce- 
lian ” vertebrae, whilst Pelodytes has them normal or “ procoelian they have ribs, but 
this type has not (see Mivart, P. Z. S., 18G9, pp. 290, 291, and. 294). Nevertheless, 
in spite of all that, I would rather put this near them—the natives of the same geogra¬ 
phical territory—than place it with any from a far country, having a great belief in 
the faculty of the Anura for modifying their internal structure, during secular periods. 
The occipital condyles (Plate 23, figs. 1, 2, oc.c.) are large, oval, and posterior; the 
occipito-auditory region is wide proximally, and narrow distally. The interorbital 
region is rather wide, lessens gently forwards, and bulges a little ; the nasal region is 
very broad, a little longer also than usual, and then the snout is very transverse. In 
the endocranium the fontanelle ( fo.) is single and large, the roof-bones more than half 
hide it, and leave it of an hourglass shape. 
Half the interspace between the occipital condyles is unossified, and the super- 
occipital cartilage (above fm.) is of the same breadth ; this is normal. But there 
is no distinction between the prootic and ex-occipital ( pr.o., e.o .) right and left; this 
I take to be a primary confusion of parts, and not due to coalescence; if they have 
been separate at all, it has been secondary and temporary. 
The bony matter half encloses the foramen ovale (V.); half the interorbital region 
is unossified ; in this part the moderately large optic fenestra (II.) is seen. The other 
half is taken up by the girdle-bone ( eth .), which simply ossifies its own ethmoidal 
territory in front, and only slightly passes into the wings; its axillae are shallow, and 
its upper part loses half its extent at the middle, in bordering the great fontanelle. 
The nasal roof and floor (figs. 1 and 2, s.n., s.n.l. —put by mistake on fig. 1) are 
well developed, the former widest behind, and the latter in front. The “ pro-rhinals ” 
( p.rh .) are small, and the angles of the floor large; there is a small “ prenasal rostrum ” 
running forwards from the thick septum nasi (s.n.). 
The palato-suspensorial arches are quite normal, but the fore part is very broad, and 
the hinder part rather feeble ; as in Dactylethra and Bombinator there is no palatine 
bone, and the pterygoid ( pg .) is feeble like that of a young Common Frog; it scarcely 
affects the cartilage to which it is applied, and a considerable pad of cartilage forms 
the facet of the movable “ pedicle ” ( pd .). The re-entering angle of the pterygoid 
and suspensorial cartilage is a right angle, and in it the Eustachian passage (eu.) is 
seen—it is large, oval, and transverse. 
* Dr. Gunther, who gave me my specimen, predicted that I should find it a very generalised type; 
this is quite true, for I am completely puzzled as to where it ought to be placed. The “Family” in 
which systematists put it, namely, the “ Discoglossidae,” is merely a “ Cave of Adullam,” to which all 
sorts of irregular, lawless, and aberrant types are relegated. Pelodytes and Calyptocephalus have procoelian 
vertebrae, whilst in Xenopirys and Viscoglossus they are opisthoccelian. 
Q 2 
