C() MR. W. K. PARKER ON THE STRUCTURE AND 



7. There is a short prenasal rostrum. 



8. The pro-rhinals are nnusually long and folded over. 



9. There is no inter-stapedial, and the siipra-stapedial is confluent above. 



10. The suspensorium of the jaw is of great depth. 



11. There is a small extra-hyal on each side. 



1 2. Most of the investuig bones retain their early condition as thin ragged lamina;. 

 On the whole this instructive skull shows that Tomopterna is a Frog close akin to 



the species of Rana, but leaning towards the Cystignathidre ; but it does not lie 

 directly between the two families, for it has been modified, as a Frog, much as those 

 neckless types Cacopus, Diplopehna, and Callula have been modified, as Toads. 



Here we have a problem relating to the influence of territory ; that which gave the 

 apoplectic hole to the toothless kinds, doubtless thrust together the head and shoulders 

 of this tooth-bearing type. 



IG. r tjxicep)halus riifescens. — Adult male ; 1 inch 5 lines long. India. 



This a much slenderer, smaller, and more warty kind of Frog than the last. Its 

 toes are much more perfectly webbed in my specimen than in several specimens of 

 Tomopterna hreviceps in my collection. Dr. Gunther says that the interdigital 

 membrane is equal in both kinds (ibid., p. 412). 



The outline of the head is so elongated and pointed as to be almost triangular — 

 a great contrast to the last. 



Dr. GiJNTHER says that the eyes ai"e much smaller than in the last kind (p. 412) ; 

 this is a correlate of the narrowing of the skull forwards. 



The length is to the greatest breadth as 8 to 8| ; for although narrow in front, this 

 skull is very wide behind. 



The occipital condyles (Plate 14, figs. 1 and 2, oc.c.) are large, remform, inferior, and 

 wide apart ; an evenly emarginate tract of cartilage, two-thirds their own width, 

 separates them. This basioccipital cartilage is twice as broad as the superoccipital 

 synchondrosis, and the bony masses formed by the extensively spread jsrootics and 

 ex-occipitals {pr.o., e.o.) are much nearer together above than below; there they 

 deviate more and more from the foramen magnum to the foramina ovalia (V.), which 

 they reach below. 



Above (fig. 1), there is a large transversely oval space unossified, and with small 

 secondary fontanelles ; the prootics meet in front of this, and are far extended in 

 the roof Laterally, the prootics and ex-occipitals ai"e confluent, but only artect the 

 postci-ior, and the arch of the anterior, canals (fig. 1, a^^.) ; the rest of the divergent 

 ear-mass is soft: below, an oval floor is left soft to the vestibule, externally (fig. 2, vh.). 



The actual cranial cavity is three times as wide in the post-orbital as in the ant- 

 oi'bital region ; far from being an extremely wide skull, it lessens forwards, to become 

 one of the narrowest known. Its lateral margins are sinuous, the middle bellymg a 



