186 MR. W. K. PARKER ON THE STRUCTURE AND 



figs. 1, 2), but the intrinsic roof of the lattei-, and the secondary roof of Nototrema, 

 dilate the top at opposite ends, so that whilst they have the same actual outUne, this 

 is reversed ; the skull in this kind is twice as wide at the temples as in front, and in 

 the other twice as wide in front as at the temples. 



Moreover, the skull is almost as completely roofed as in the narrow- backed Oriental 

 Tree-frogs (Polypedatida3), for only a httle of the membranous fontanelle is naked, 

 as the roof-bones converge rapidly, and for half their extent form a " sagittal sutm-e." 

 Somewhat hooked in front, the fronto-parietals {f-P-) insert their point under the 

 nasals («.), but leave a pentagonal tract of the girdle uncovered, in front of the 

 fontanelle, and also expose, right and left, the small semi-ossified superorbital eaves 

 {s.oh.). Above, in front, this bony part is hidden by the conterminous nasals (n.), and 

 below, in some degree, by the inner end of each palatine (^^ct.), and by the toothed 

 boss of each vomer (t'.). The dilated end of each ethmoidal wing, and nearly all the 

 nasal region, are left untouched by the girdle-bone. The nasal roof {al.n.) is formed by a 

 pair of large, but narrow, crescents, that are confluent by their backs with the top of the 

 septum {s.n.) ; the whole tract is narrow-waisted. So also is the floor (fig. 2, s.n.), but 

 it is twice as wide, and at its angles spreads into leafy lobes, that grow well into the 

 fore end of the maxillaries {mx.). The outer nostrils {e.n.) are not wide apart, although 

 the snout is transverse ; yet the outHne of the bones {px.) is crescentic. The inner 

 nostrils are one-half larger, and their distance is one-half greater. The transverse 

 snout-margin has three well-formed projections, namely, a terete prenasal, and the 

 two pedate, out-turned pro-rhinals (p.rh.). Tiie appendices of the nostrUs («./'.?{.?-.) 

 are of the typical size and form. 



The palato-suspensorials are sti'ong, the front bar {jM., 'pr.pa.) is directly transverse 

 and cultrate, and the lateral part {pa. to pg.) gently arcuate. The palatine bone {pa.) 

 is thin, falcate, and narrowest in the middle ; it is but little united to the cartilage. 

 The pterygoid {pg.), as usual, runs up along the post-palatine bar to the curved end 

 of the palatine bone ; it has largely affected the cartilage beneath, and has run outwards 

 into the post-palatine lobe, thus making what is generally only seen during meta- 

 morphosis (see in Pseudis, Plate 12, fig. 4), a permanent structure ; for at one time 

 all the arch which now stretches from the ethmoidal wing to the jugal lobe was 

 antorhital, and it really belongs to the palatine. The pterygoid (fig. 2, pg.) seems, as 

 seen from below, to have two sub-equal forks, but the side view corrects this (fig. 3), 

 and the quadrate region is seen to be of considerable extent ; it is jiartly ossified. 

 The fork of the boue {j^g.) is shai'p, and thus the Eustachian opening {eu.), which is of 

 the medium size, is oval. The inner Ibrk (j^cZ.) is formed of the cartilaginous pedicle 

 and pterygoid bone ; the latter almost obliterates the joint, but not so much as in 

 Hyla albomarginata. The quadrato-condyle {q.c.) is a very finely finished trochlea, 

 for the sohd cylindroidal condyle of the mandible (fig. 3 ar.c). The auditory outworks 

 have but a middling development ; the annulus {a.tij.) is not small, but its horns are 

 wide apart ; tliere is a good sized tympanic cavity. The stapes (fig. 5, st.) is large. 



