84 ]\IH. W. K. PARKER ON THE STRUCTURE AND 



Nor has this generalised growth (both of cartilage and bone) allowed any deficiency 

 of roof below the parietal region ; there is only one, the main, fontaneUe : this space is 

 barely covered by the shortish frontal end of the roof-bones {/■[>■)■ 



Tlie roof-bones are completely re-united, and the frontal sutiive is partly closed, as 

 well as the wliole of the sagittal ; the skull is sub-sulcate towards the mid-line 



(fig.l.). 



These roof-bones leave much of the endocranium uncovered behind as well as in 

 front ; a little temporal wing, and a moderate orbital plate is formed by them. 



The parasphenoid retains the form it had in the large larva (Plate 2, fig. 2, pa.s.) ; 

 and it is very characteristic of Pseudis, being a dagger, gapped at the point, with a 

 wide elegant "guard," and no "handle." 



Tlie large girdle-bone {eth.) extends its osseous substance half across the cheeks, 

 half along the internasal region, and it trespasses on the orbito-sphenoidal headland. 



Together, these elements make the interorbital part of the cranium (its anterior 

 two-thirds) a boat-like structure, gently narrowing forwards. 



Then, on a sudden, it widens again, passing out into the palatal and nasal 

 structui'es. 



Above (fig. 1, n.), the elegant conchoidal nasals cover much of the roof, and run down 

 over the ethmo-palatine wings, but they do not hide the middle over the front 

 extension of the creeping ossification from the girdle-bone ; above (fig. 1), the soft pre- 

 nasal {p.n.) finishes the face. 



The ectosteal palatine (fig. 2, 'pa.) binds under the half-ossified ethmo-palatine ; it is 

 falciform, with the narrow handle inwards, far from that of its fellow of the other 

 side. 



Hiding the semi-osseous sub-nasal plate, except in front and in the middle, are 

 the two vomers (Plate 2, v.), they are sub-reniform, with a lateral spike ; behind, they 

 are massive and dentigerous : this lenticular part is like what is seen in several Frogs 

 (both " Platydactyla " and " Oxydactyla ") from the Notogcea. 



The internal nostrils (fig. 2, i.n.) are large and round ; the external nostrils (fig. 1, c.n.) 

 are moderate in size and are guarded by two valvular cartilages, the inner and outer 

 upper labials. 



The arc of cartilage running from the palatine to the pterygoid becomes thin, but I 

 cannot find that it is segmented; the latter bone {pQ-) is pointed in front, then 

 becomes very broad, and this wide part forks into the sheath of the pedicle {pd.) 

 and a posterior process. 



The posterior process becomes sub-vertical, bindmg the inside of the suspensorimu to 

 the condyle of the quadrate {q-c). 



The inner fork arches inwards and enclothes the stunted pedicle {pd.) up to the 

 condyle, which glides on a pad of cartilage on the fore-face of the auditory capsule 

 (fig. 2.). 



