i2'i MR. W. K. PARKER ON THE STRUCTURE AND 



5. The absence of the secondary f'ontanelles. 



6. The increasing width, forwards, of the cranium, involving the great breadth of 

 the girdle-bone. 



7. Snperorbltal projection of the ethmoid cartilage. 



8. The width, convexity, and solid rostral end of the nasal region. 



9. The thi'ee anterior siibnasal ossifications. 



10. Slightness of jaalato-suspensorial arch, with its fixed pedicle. 



1 1 . Bony quadrate. 



12. Oblong, oblique, open annulus tympanicus. 



13. Generalised columella, without supra-stapedial process or infra-stapedial segment. 



14. Absence of hyoid band and of autero-lateral lobes of basal plate. 



15. Inferior position of pre-maxillaries. 



16. Reversed shape of fronto-pai-ietals. 



17. Extensive double growth of supratemporal region of squamosal. 



18. Solidity and arcuate form of vomers. 



19. Massiveness of upper labials, and union of the inner pair witli pre-maxillaries. 



20. Absence of septo-maxillaries. 



These twenty marked characters of difference from the type show how far removed 

 this Frog is from the Ranidse ; its generalised nature is so gi'eat that I shall have to 

 refer to it for comparison when I come to the Polypedatida), the Hylidae, the 

 Phryniscida3, the Engystomidce, and the Hylaplesidte. 



Fourth genus. Cahjptocephalus, 

 30. {A) Calyptocephylus Gayi. — Adult female; 5^ inches long. Chili. 



(A) Tlie adult. — This large, massive, and almost ganoid skull (Plates 21, 22) is, on 

 the whole, very Ranine, but it has retained a copious overgrowth of granular sub- 

 cutaneous bone, which makes it like a strong rough helmet. 



Its general form is lialf a short oval ; it is similar in outline to rather more than the 

 narrow end of a shoi't Hen's egg ; for its outline narrows in again behind. Compared 

 with its length (from snout to occipital condyles) the breadth is as 4^ to 3, and the 

 quadrate hinges project 2 lines beyond the occipital hinges, making the skull one- 

 eleventh longer at the outside. The actual measurements are — 



1. Greatest breadth, 2 inches 5 lilies. 



2. Length from snout to occipital condyles, 1 inch .0 lines. 



3. Extent of quadrate hinges behind them, 2 lines. 



This skull carries the peculiar Batrachiau type to its greatest degree, viz. : tlie great 

 width as compared with the length. 



So great is the development of the investing bones that the endocranium is almost 



