328 MU. F. K. BICDDAUD ON THE AKATOMY [^Pl'- •^ 



which I pi-ovisionally at least identify with Moyalophrys nasuta. 

 The most obvious test to apply for the solution of this question 

 is the exit of the spinal nerves. Now 1 find that :i stout nerve 

 issues from the spinal cord just in front of the stout and expanded 

 transverse process of the sacral vertebra; and that an equally 

 stout nerve issues behind this transvei'se pi-ocess in the angle 

 bet-sveen it and the coccyx. There is none between the two. 

 Hence the sacrum is composed of but one vei-tebiu as in most 

 othei" Frogs. 



A second character is the pi'ocoelous excavation of the vertebral 

 centra. A part of the definition of Megalophrys by Boidenger is 

 " VertebriB opisthocplian." This character, used by him in the 

 tabular * discrimination of the genera of PelobatidiV^, is again 

 made use of in the fuller description of the genus Megalophrys t. 



It is, however, in the characters of the sternum that tliis 

 species chiedy differs from other species of Megalophrys. Among 

 the charactei'S used by Boulenger J to define the fainily Pelobatidse, 

 one is stated as follows, viz. : " The omostei'num is constai^tly 

 present, but small and cartilaginous." That this definition is 

 not absolutely true was subsequentlj^ shown by Mr. Boulenger 

 himself §, who asserted that in Scaphiopiis solitaries there was 

 " no omosternum." The shoulder-girdle and sternum of the 

 genus Megalophrys have been figured and described by Pai'ker || 

 in Megalophrys montana. The omosterniim is minute and the 

 sternum is ossified neai-ly throughout, an inconspicuous cartila- 

 ginous xiphisternum only being left at the free exti-emity of tlie 

 bone. These characters {inter alia) are used by Mr. Boulenger 

 in his definition of the genus Megalophrys, a,nd therefoi'e 

 presumably also apply to M. nasuta. Whethei- the sternal 

 apparatus of M. longipes has been examined I do not know. In 

 the Frog upon which I repoi't in the present connnunication, the 

 chaxactei's of the sternal apparatus ai-e diffei'ent from those 

 which ha,ve been I'efei'red to in Afegalophrys onontana. Both 

 sternum and omostei-num ai-e veiy Avell developed. 



The omosternum, instead of being a small oval plate of cartilage 

 as it is represented to be by Parker in Megalophrys onontana., has 

 a foi-m which apai-t from details is moi'e like that of Rana 

 escnlenta. It is actually ten millimetres long, and its proportions 

 to the rest of the sternum a,i-e therefore much more like those 

 of Paliidicola hibronii figiu'ed by the same author^. Although, 

 as in M. montana and other Frogs, the pi'ocoracoids are bent veiy 



* C:\t. Ratr. Sal. 1882, p. 433. 



t Ibid. p. 1.1.2. X Loc. cit. p. 132. 



§ P.Z.S. 1809, p. 790. 



II A Monograph on the " Stnifture and Development of the Shoulder-Girdle," 

 Ray Soc. 1868, p. 78, pi. vii. tig. 8. 



% It is by no means certain in es-ery ease that the species described by Prof. 

 W. K. Parker in his Monojiraph of the Shonldev-Girdle have been correctly 

 identitied. I lind for example that the sternum of JSi/Ja coevulea {=:" CaJainifes 

 c.yanea" of Parker's noinenclatnre) is not as Parker has figured it {loc. cit. pi. vii. 

 lig. 6), but exactly resembles the sternum of " Acrodiites dauditiii" (presumably 

 a HijT^a) tignred by the same author {loc. cif. pi. vii. fig. 1). 



