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



In this lower aspect we see the bone reaching round the foramen ovale (V.), right 

 and left ; and there, inside the bony bar that divides that passage from the large optic 

 fenestra (II.) a little cartilage remains. 



The orbital part of the skull is almost square, but it is wider in front than m the 

 temporal region, which is pinched and bevelled. In front, the endocranium widens up 

 to the ethmo-palatine wings, but the roof-bones are scant, externally (fig. 8). 



The single fontanelle is heart-shaped, and occupies the middle third of the roof, or 

 thereabouts ; the hinder tegmen is longer than the tract in front of the fontanelle. 

 The girdle-bone (eth.) is half the size of the cranial "barge," for it is of great width, 

 through the widening forwards of the skull, and it reaches from the optic fenestra to 

 the verge of the nasal roofs {al.n.), above ; only a small selvedge is left there, but the 

 foremost third of the subnasal tract (s.n.) is unossified below; behind and above, the 

 girdle-bone and prootics are confluent. 



Both under and over views (tigs. 8 and 9) give the idea of njlat skull ; but the side 

 view (fig. 10) corrects this error. Indeed, it is a very remarkable skull for a Batrachian, 

 and more like that of a young Lizard with its high swelling brain, for the temporal 

 region is very convex, and all along the height is considerable, and in remarkable con- 

 trast to the skidls of some of the large Tree-frogs {e.g., Rhacophoi-us, Phyllomedusa) 

 whose skulls are as flat as those of the Ray tribe. The orbital rim is developed along 

 the fore half of the orbit, but not like a distinct flap ; it is emarginate rather than 

 lobate. 



The nasal region is broad, and emarginate in front, there being no prenasal projec- 

 tion, and the bulging of the down-turned nasal roofs (al.n.) gives a somewhat bilobate 

 form to the broad snout. Yet the snout is not wider than in the larger Oriental 

 " Polypedatidee," and not so broad as in Rhacophorus. 



The nasals (h.) above, and the vomers (r.) below, leave the snout bare up to the 

 rather small premaxillaries {px.), between whose processes the narrow pro-rhmals 

 (fio-. 9, p.rh.) are impacted. The subnasal laminae {s.n.) do not go far into the 

 maxillaries {mx.), and these diverge rapidly from the nasal floor. 



Nevertheless, the ethmo-palatines have the edge of their adze-shaped pre-palatine 

 blades {pr.pa.) set between the wall and floor of these bones, and where the post- 

 palatines end, there the cheeks are becoming very wide. The osseous counterparts of 

 these tracts {pa.) are double on each side ; the inner is the larger, and is not far from 

 its fellow of the opposite side, and these two internal palatines are thin lanceolate, 

 sharply crested bones. These sharp crests look as if they had once {in a secular sense) 

 carried teeth ; the saw-like crest on the same bones in Bufo agua suggest the same 

 thing. The left outer bone is three times the size of the right, which is a little oval 

 scale ; these bones are inverted in the figure (fig. 9). 



The well curved falcate fore region of the pterygoid (fig. 8, pg.) reaches half way 

 over the prepalatine blade ; one of \is forks (fig. 9, jx/.) is very short. 



The core of the palato-suspensorial arch is persistent throughout, and can be seen, 



