184 
MR. W. K. PARKER OK THE STRUCTURE AND 
The investing bones are slight, but rather strong; the fronto-parietals (f.p.) are more 
developed than in many Hylce, and creep over some considerable tract of the temples, 
clamping the ridge of the “anterior canal” (a.s.c.). They cover in a little of the 
exposed membranous roof ( fo .), and diverge only a little to their pointed fore end. The 
nasals (n.) are crescentic trowels, that stop in front with the bony deposit, and thus 
are far off from the nostrils ; they are a moderate distance from each other. There 
are no septo-maxillaries, that I can find; the other outside bones ( px ., mx., q.j., sq .) 
have the typical development. The parasphenoid ( pa.s .) is a very elegant dagger, at 
first very wide, and then running to a fine long point. The guard is composed of two 
long slender bars ; the handle is broad, short, triangular, and anchylosecl to the skull. 
The vomers (v. ) are very large, perfectly typical in form, and have an oval toothed 
boss, they are only separated by the septum, behind. 
With an outer form more Ranine than that of the species of Hylce, this skull yet 
shows a considerable number of specialisations that are different from what is seen 
in a typical Frog :— 
1. The skull is more flattened out. 
2. The occipito-otic region is one continuous mass of bone, running to the front of 
the optic fenestra. 
3. The girdle-bone takes up half the anterior sphenoidal region, and half the nasal. 
4. The superorbitals are present, but ossified. 
5. The main fontanelle is open through the arrest of the roof-bones; and the lesser 
spaces are ossified. 
6. The pedicle is tied down by the pterygoid, 
7. The quadrate is ossified. 
8. There is no septo-maxillary. 
9. There is neither inter- nor supra-stapedial. 
10. There is no fore lobe to the small basal plate, and the thyro-hyals are anchylosed 
together and ossify much of its middle part. 
11. The palatines have a cultrate ridge. 
Third genus. Nototrema. 
52. (A) Nototrema marsupiatum .-—Adult male ; 1-f inch long. South America. 
This skull (Plate 33, figs. 1-5) has all the massiveness of that of any stout Toad, 
and is in extreme contrast with what is found in some of the species of Hyla —such 
as II. phyllochroa, and II Eivingii. It is flat at the top and wide, but is also very 
high or deep, for a Batrachian. 
The proportion borne by the bony, to the soft, tracts of the endocranium is not 
much greater than is common even in the genus Rana, but where bone is, there it is 
strong and rugged, and the investing bones might belong to the skull of a small 
Crocodile, both for their strength and sculpture. 
