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



with each other, they differ from the more typical Anura of the European sub-division 

 of the Palajarctic region. They differ greatly from the normal Biifo, as well as from 

 the normal Rana, and they are isomorphic, more or less, with types in the " Notogaja," 

 to which they can claim only the remotest Batrachian relationship. 



The main characters by which Alytes differ from the common typical Frog are : — 



1. The flattened, very feeble skull, as a whole. 



2. The open state of the fontanelles, through the deficient growth of the roof-bones. 



3. The fusion of the normal pair of secondary fontanelles into one. 



4. The presence of a clear superorbital edge to the skull, and the articulation with 

 it of a large, distinct superorbital cai-tilage. 



5. The nasal roof imperfect, and the " rostrum " well developed. 



6. No septo-maxillaries. 



7. Occipito-otic bones continuous. 



8. Quadrate region partly ossified. 



9. Supra-stapedial confluent. 



10. An endosteal " articulare." 



11. Cerato-hyal wide, and basal " notch " very large. 



12. A V^i^haped ectosteal basi-branchial, and periosteal cartilages on thyro-hyals. 



Fifth Family. Hyperoliid^. 



Genus Hyjyerolius. 



32. Ilf/peroHus (Uperolcia) mai-moratus. — Adult female ; l| inch long. Paramatta, 

 Austi'aha. 



This type represents the " Uperoliidre " of Gunthek ("Batr. Sal.," p. 39), but Pro- 

 fessor MiVART (P. Z, S., 1869, p. 291) melts this lesser group into the "Alytidse;" 

 the correspondence in certain characters, however, gives them no real title of near 

 relationship. This more extended group of "Alytidse" must be taken as a convenient 

 temporary zoological bundle ; a very small spark will devour the " tow " that binds 

 these alien types together. 



This skull (Plate 24, figs. (5, 7) is evenly semi-elliptical in outline ; its breadth is 

 a little greater than its length, and the quadrate condyle {q.c.) is only opposite the 

 foramen ovale (V.). 



This skull is at once seen to bo both generalised and arrested ; yet it belongs to a 

 mmority among its Australian congeners, in having its fontanelle covei-ed. Altogether 

 it is more like the skull of a young Common, than of an old Obstetric, Frog. 



It is, indeed, more like the typical skull than that of the " Cystignathidte " of 

 Australia — Lymnodynastes, Camariolius (Plates 18 and 19)^whose skulls approach 

 tho.se of the Tree-frogs of the same region. The occipital-con dyles are almost hemi- 

 spherical ; they are posterior, and are sepai'ated by a straight -edged interspace lai'ger 



