1907.] OF A FIIOG OF THE GENUS MEGALOPUUYS. 329 



much forwards, their articulation with the omosternum in M. nasiUa 

 is not by any means so fai- foi-wards as it is figui-ed by Parker 

 in M. montana. This articulation is plain enough in M. nasuta. 

 Above this articulation and for the entire shaft the omosternum 

 is clearly calcified. It expands above into a circular cartilaginous 

 plate which lias a crescentic outline anteriorly and is wider than 

 the shaft. The procoracoidal cartilages at and near both points 

 of ai-ticulation with the omosternum are also calcified. The 

 sternum consists of a bony style as in Megalophrys montana ; but 

 there are differences in detail. In the first j)lace, the bone is 

 longer in proportion to its width in M. nas'ata^ and it does not 

 expand so markedly in width towards its postei-ior termination 

 as is represented in Pi-of . Pai-ker's figure of Megalophrys montana. 

 In the second place, M. montana is characterised by a cartilaginous 

 xiphisternum which " is but little extended either laterally oi- 

 axially beyond the shaft-bone." This is not at all the case with 

 Megalophrys nasuta, where the xipliisternum is a broad and 

 expanded plate, having postei'iorly the semicircular cheese-cuttei-- 

 like outline which is so usual among Frogs. On the whole, 

 therefore, there are some diflferences between the two species. 



The sternum of this Fi-og is in fact pai-ticularly large as 

 compared, for example, to that of its ally Pelobates Juscas, witli 

 which I have compared it in this and in some other details of 

 structure. The diflference of size is, of course, actual in view of 

 the much larger dimensions of the Frog which I describe here as 

 compai-ed with the rathei- small Pelohates fuscus. In Pelohaies 

 the total lengtli of the body in the individual measured w;is 

 47 mm. and the total length of the sternum 16 mm., the sterninu 

 being therefore roughly one-thii'd of the length of tlie bod\'. 

 The coi-responding measurements in the Frog descriljed here 

 were 135 mm. and 60 mm., the proportions therefore neai-ly 

 approaching one-half. The relationship of the sternum to the 

 underlying viscera shows corresponding difierences in the two 

 genera. In Pelohates the sternvmi hardly extends back beyond 

 the heart and pericardium which, liowever, it fully covers. The 

 liver is left largely exposed. In " Megalophrys nasuta " the 

 sternum passes a considerable distance beyond the liver-lobes, 

 the heart being beneath almost the commencement of the sternum 

 proper. 



So far as I can gather from the memoirs already quoted which 

 deal with the species Megalopjhrys nasuta, there has been no 

 actual description of the sternum in this particular species. But 

 since several systematists use the occurrence of a rudimentary 

 omosternum as a generic definition, the matter must have been 

 looked ifito by them, or by some of them. So far as present 

 views upon the classification of the Anura go, it is clear that I 

 should be hai'dly wrong in instituting not merely a new species 

 but a new genus for this Frog, on account of its divergent sternal 

 characters, as compai-ed with those that have already been described 

 in the genus Megalophrys. In contradiction, however, to this 



