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



strongly back to keep to the margin of this passage as the hinder half of its natural 

 skeleton. 



The quadrate region of the suspensorium (q.) is not ossified by the " quadrato-jugal " 

 (q.j.) — shaped like a Serpent's tooth ; the saddle-shaped condyle (q.f.) is very large, but 

 does not reach to the extreme angle of the suspensorium (figs. 7 and 8). 



The "amudus," like the Eustachian passage, is small, the band itself is wide (fig. 6, 

 a.ty.), and it is a perfect ring ; the whole tympano-Eustachian cavity is small, but the 

 columella and stapes (fig. 10) are of the average size; the latter (s-^) is almost a long 

 triangle, but the posterior and inferior edges are rounded : the anterior margin is con- 

 cave, fitting into the inter-stapedial. 



This latter jiart [i.sf.) has a deep saddle-shaped condyle for the stapes ; it is unossified. 



The medio-stapedial (m.st.) is nearly all ossified; it is gently arched, and not much 

 expanded where it articulates with the inter-stapedial. 



The extra-stapedial (e.st.) is very large, elegantly heart-shaped, peltate in aiTange- 

 ment — its cartilaginous " handle " passing from the medio-stapedial bone mto the inner 

 face of the main plate obliquely ; and it covers half the concave, wide " annulus." 



There is no supra-stapedial band — a part which is seen even in the peltate extra- 

 stapedial of Biifo vuhjaris (Phil. Trans., 1876, Plate 54, figs. 7 and 8) ; but here we 

 have, suddenly, as it were, the columella of Ptpa and JJaet ijlethra over again, with the 

 difference of a short and soft inter-stapedial (Phil. Trans., 1876, Plates 59 and 62). 

 The extra-stapedial part is mostly orbicular in the Oriental Ranee, but not large. 



The mandible (fig. 8) is normal, with the exception of the fore part of the dentary 

 (c/.); the crest which grows up from that bone in front in other species is here a high 

 strong spur — an imitation, in bone, of a large canine tooth : in old age (according to 

 Dr. Gunther) it becomes capped with tooth-substance. It " cuts the gum " early, 

 and soon dents the side of the palate, which becomes hollow to receive it. Moreover, 

 the bones aU round this excavated part are greatly modified ; this is partially seen 

 on one side in R. hexadactyla (fig. 2), with its much smaller dentary crest. ''^ 



Where the palatine plates of the premaxillaries and maxillaries meet (fig. 7, pa;., mx.), 

 their processes project far inwards ; this is to leave room for the socket of the qua^i- 

 canine ; the hole is bordered on the outside by the dentary edges of these bones at 

 their j unction. 



Not only so. Where they meet on the outside (fig. 8), there they rise high at their 

 junction, and leave an angular space or gap in the toothed margm of the fore face. 

 There are no septo-maxillaries ; both the quadrato-jugal (qj-) finishing the cheek, 

 and the squamosal (sq.), in the temporal region, are very strong and elegant bones, but 

 the latter is very remarkable, even for a Frog. The bone seen from above (fig. 6, sq.) 

 is a sickle, its rough notched handle lying on the tegiaen tympani ; running obliquely 



* Dr. GuNTilKK looks upon tliis quasi-canine as a special thing — a tendency, so to speak, to produce a 

 tooth, here ; my own mind leans to the opiuion that it is not a rudiment, but a remnant; nearly all the 

 Indian kiuds show it more or less, and their Common Parent may have had large genuine teeth in the front. 



