340 MR. F. E. BEDDARD ON THE ANATOMY [Apr. 9, 



Rana according to the same observer ; that is to • say, its origin 

 does not extend on to the tough membrane which lies between 

 the posterior process of the body of the hyoid and the thyro- 

 hyal. Nor, in Megcdophrys, as again in Pelodytes but not in 

 Rana, is any pai-t of the stei-nohyoid inserted on to this membrane. 

 The reason for this is clear in the case of Megalophrys. For in 

 that Frog the very large posterior petrohyoid comjDletely covers 

 over this space and would allow of the insertion of no muscle 

 "upon it. 



The Suhhyoideus (the posterior poi-tion of the submaxillaris of 

 some authors) is rather different in the Frog which forms the 

 subject of the present communication from the corresponding 

 muscle of Rana. In the latter it is a hyoidean muscle and arises 

 in the extreme lateral region of the hyoid cornua. In Megalophrys, 

 where these cornua are absent, I ti'aced the muscle to the wall of 

 the skull just behind the tympanum. 



The Hyoid cartilage is not like that of either Pelodytes or Pelo- 

 hates, both of them allies of the present genus. Nor does it recall 

 that of Rana, for I can find no trace of a cartilaginous cornu 

 principale or hyoid arch proper ; and as I have already stated, the 

 subhyoideus muscle arises from the skull-wall and did not serve to 

 guide me to a hyoid bar. 



Xenophrys monticola obviously comes nearei' to my species than 

 any other species of the hyoid of whici! I can find a description. 

 Of this Frog the late Prof. W. K. Parker wrote* : " I could find no 

 cartilage in the hyoid arch from the Eustachian opening down- 

 wards until I reached the hypohyal region.'" The outline is very 

 similar to that of Megalophrys nasuta. There is towards the 

 upper end of the diverging body of the hyoid (the hypohyal of 

 Parker) a nick in the cartilage on the outer side. This, as I 

 think, represents the nick which I figui'e here in Megalophrys 

 nasuta, and to which what appear to be vestiges of the hyoid 

 arches or ceratohyals are attached. Behind this in Xenophrys 

 monticola, as in Megalophrys nasuta, the body of the hyoid forms 

 a bay from which ai-ises in my species the anterior petrohyoideus. 

 There is no more tiuce in Xenophrys than in my species of an 

 anterior lateral process of the body of the hyoid, unless indeed 

 the hypohyal really represents that, and the true anterior process 

 of the body of the hyoid is absent. In both these Frogs, however, 

 the posterior lateral process of the hyoid is present, and the thyroid 

 bar is well-developed and ossified, but without the spur-like carti- 

 laginous epiphysis of Megalophrys nasuta. 



The accompanying figure (text-fig. 97) shows the hyoid of Mega- 

 lophrys nasuta. The body is fairly stout and shows no traces of 

 an anterior latei-al process. The anterior, " hypohyal,'"' process on 

 each side is a somewhat spoon-shaped piece of cartilage in the 

 same straight line with the rest of the body of the hyoid. It is 

 not bent inwards as in Pelohates and Pelodytes'^. Nor could I 



* " The Skull in the Katrachia," Phil. Trans. 1881, pi. 23, fig. viii. 

 t P. Z. S. 1897, pi. xxxv. figs. 10, 12. 



