DEVELOPMENT OF THE SKULL IN THE BATRACHIA. 115 



this respect it is intermediate between that of Flcurodcma and Lyrnnodynastes, 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, Bomhinator and Alytes, however, are veiy exceptional forms, having "opisthocce- 

 lian " vertebrae, whilst Pelodytes has them normal or " proccelian ;" 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 A)iiira for modifying theu' internal structure, during secidar 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 foiitanelle {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 f.m.) is of the same breadth ; this is normal. But there 

 is no distinction between the prootic and ex-occipital ( /jc.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 interoi'bital region 

 is unossified ; in this paii 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 wmgs; its axilla2 are shallow, and 

 its upper part loses half its extent at the middle, in bordering the great fontaneUe. 



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 " prcnasal rostrum" 

 running forwards from the thick septum nasi (sji.). 



The palato-suspensorial arches are quite normal, but the fore part is very broad, and 

 the hinder part rather feeble; as in Dactylethra and Bomhinator 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" (j^d.). The re-entering angle of the pterygoid 

 and suspensorial cartilage is a right angle, and in it the Eustachian passage (cti.) is 

 seen — it is large, o\al, and transverse. 



• Dr. GusTHEK, who gave me my specimen, predicted that I should find it a very generalised type; 

 this is quite true, for I am completely puzzled us 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. Pelodi/les&ud CaUjptocephalui have proccelian 

 vcrtebnc, whilst in Xniopkri/s and I>/(.co(//o.ss«« they are opisthoccelian. 



Q 2 



