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



It differs from that of the typical Frog in the following jjarticulars : — 



1. It has no true teeth. 



2. There are homy imitations of the Ranine teeth, 



3. The whole skull is as massive and rough as the " norma " is light and smooth. 



4. The endocranium is much more ossilied, and is shorter and broader. 



5. The nasal roofs are imperfect. 



6. The pro-rhinals are small and inbent. 



7. The palato-suspensorial arch is very large, and the pterygoids bind upon the 

 pedicles, and fix them, and articulate with the parasphenoidal w^ngs. 



8. The massive palatines are united by suture at the mid-line and also bear a 

 serrated carinate crest ; the core of cartilage is divided. 



9. The quadrate is largely ossified. 



10. The supra-stajDedial is confluent above, and the inter-stapedial is largely ossified. 



11. The stylo- and hypo-hyals are absorbed. 



12. The fore lobes of the basal plate are detached. 



13. The premaxiUary on the right, and the vomer on the left, side, have a super- 

 numerary bone. 



14. The whole skull is of great height, as compared with the depressed " norma." 



15. The orbits are largel}^ roofed over, and the auditory regions almost hidden, by 

 the investincr bones. 



58. (A) Bufo chilcnsis. — Adult male ; 3 inches long. Arequipa, Peru. 



On the whole, the skull of this species is so much like that of B. pantherinus that I 

 have not figured it ; there are some points, however, in which it differs from it. The 

 palatines (Plate 35, fig. 6, pa.) are not so much crested as in that kind, but each bony 

 tract is composed of two pieces^ obliquely overlapping one another. The outer piece 

 on the left side is twice as large as the other ; the converse of this takes place on the 

 right side. 



The stapes (fig. 5, st.) is more oval, and has an equally large boss ; the columella is 

 shorter, and more regular in form, there is no inter-stapedial segment, proximally, and 

 the medio-stapedial is widely emarginate ; its two oblique lobes are uno.ssified. 



The extra-stapedial (fig. 5, e.st.) is a broad spatula, and sends up a strong supra- 

 stapedial band {s.st.), which is confluent, above. 



58 (continued). — (B) Tadpole of Bufo chilensis. — Total length, f inch ; tail, h inch ; 

 hind legs, -^q i'^ch. Arequipa, Peru. 



This is the youngest of the " fry" of tliis large Toad examined by me ; the recently 

 metamorphosed individuals were no larger than the Common House Fly. 



This skull (Plate 38, figs, 7, 8) is only two thirds the length, but the same breadth, 



