182 ME. W. K. PARKER ON THE STRUCTURE AND 



labials {I. I.) are thick scooped crescentic lumiles ; the upper (or temporary) labials 

 ((/./.) are large, thick, and lozenge-shaped, with a deep notch outside. The hyoid 

 (fig. 9, c.hy.) is very elegant. The lobate lower part is lozenge-shaped, and is joined 

 to its fellow by the normal square mass of soft cells. The condyle and the condyloid 

 cavity on the suspensorium (fig. 9, between q. and sj:).) are very large, and the stylo- 

 hyal process is shaped like a Tiger's claw, broadly uncinate with a definite point ; this 

 tract is separated from tlie hinder distal lobe by a deep notch. 



Altogether, this is a very peculiar chondrocraniun: ; tlie next stage, in another genus 

 of the "Hylida3 " {Nototrema, Plate 30, figs. 10-13), will show still further the pecu- 

 liarities of the skull in the Tadpoles of this group. 



Second genus. Litoria. 

 51. Litoria iimvmorata. — Adult male ; 1^ inch long. Australia. 



The skull of this species (Plate 19, figs. 11, 12) differs considerably from that of 

 the wide-backed Australian Tree-frogs already described, viz. : Hijla Eivingii, and 

 H. j^hyllochroa. In some respects it comes nearer that of i/. alhomarginata (Plate 32, 

 figs. 6, 7), a Neotropical species, and in others it is not so far removed from that of a 

 typical Rana. 



It is rather strongly built, and is not so flattened out as those I have been describing; 

 in many things it shows characters that indicate affinity to other Families. The 

 breadth is to the length as 11 to 10, and the quadrate condyles reach to the middle of 

 the stapes {q.c, st.) ; hence it is a medium skull in these respects. So, also, in its 

 flatness, in density of endocranial bone, and strength of investing bones, it is an average 

 skuU. The occipital condyles {oc.c.) are of the medium size; they are postero-inferior, 

 reniform, and are separated by a convex line of basal bone gi'eater than their own 

 breadth. The epiotic eminences over the posterior canals {p.s.c.) reach neai'ly as far 

 back as the occipital condyles; then the other canals (a.s.c., h.s.c.) are large, but the 

 parotic wings, although widely extended, are narrow and run to a rounded end (t.tij.), 

 which, at the point where the squamosal (sq.) binds on, is unossified. 



But the whole hind skull, with this exception, and with the exception of the basi- 

 sphenoidal region, is all solid bone up to the optic fenestra (II.). The hinder 

 tegmen cranii is well ossified, but here was seen what is evidently rare in the Hylidse, 

 namely, two large secondary fontanelles ; they are, however, filled in with periosteal 

 bone, and are traceable by means of its thinness. The sides of the mid skull form 

 a gently concave outline, inbent most at the middle; the great fontaneUe (fo.), which 

 is longer than either of the bony tracts above, is a long oval, has but narrow tegminal 

 margins, and is a little roofed over by the fronto-parietals {/.p.). The optic fenestr£© 

 (II.) are of medium size, and have a tract of cartilage nearly of their own extent in 

 front of them ; from thence bone — the gu-dle-bone (eth.) — reaches above, to the middle, 



