1907.] ANATOMY OP THE PELOBATID.E. 905 



sartorius. Another feature is the absence of a superficial sterno- 

 radialis muscle, the existence of a special slip of the rectus 

 abdominis attached to the posterior border of the coracoid, the 

 existence of a strong muscle extending from the ilium to the 

 transverse process of the third vertebra belonging presumably to 

 the ilio-lumbar complex (which is unrepresented in Rana, &c.), and 

 the large size of the geniohyoid which covers the hyoglossus. It 

 is possible also that the family will prove to be characterised by 

 the numerous vasa efferentia not forming a rete, and by the 

 absence of a vesicula seminalis. 



Finally, the suspension of the right and left lungs up to or 

 nearly to the posterior end by a ligament is, so far as we have 

 gone, a character of this family. 



(5) The Genera of Pelobatid.^. 



The next point for consideration is the limitation of the several 

 genera treated of in this communication, which are for the most 

 part allowed as valid by systematists. The only genus which is 

 at the moment not generally allowed is Xenophrys, which has 

 been included by Boulenger * (whom others follow) in the genus 

 L&ptohrachium. So far as external charactei-s go, Megalophrys 

 might also be included, for LeptohracMiim fece and L. carinense 

 (occasionally) possess the processes over the eye which has given 

 to Megaloplirys its generic name. 



Mr. W. L. Sclater has also in the paper referred to below f 

 shown that Leptohrachium carinense may possess vomerine teeth 

 which were absent in the first individuals examined by Bouleno-er 

 but subsequently found by him J. This point is a further aro-u- 

 ment in favour'of a coalescence of the genera Xenophrys and 

 Lejitohrachium, which were formerly distinguished by the pi-esence 

 in the former and the absence in the latter of these teeth. 

 Again, the vomerine teeth of L. carinense ai^e between or even 

 slightly in front of the choante, which tends to throw doubt upon 

 the use of this position of the teeth to distinguish Megaloplirys 

 nasuta from its congener and from Xenoplirys. As to other 

 characters, it has been pointed out that Pelohates cidtripes § 

 varies in the fusion or non-fusion of the sacrum with the coccyx. 



It is not, however, I'easonable to decline to use as a chai-acter 

 an anatomical peculiarity which may happen to vary. Indeed 

 if this were the case it would be hard to frame a considerable 

 number of apparently useful specific and generic distinctions. 

 In a similar fashion, the procoelous or opisthocoelous nature 



* Boulenger, Ann. Mus. Genova, loc. cit. 



t W. L. Sclater, P. Z. S. 1892, p. 348. 



X Ann. Mus. Genova (2) xiii. 1893, p. 344. 



§ See Boulenger, ' The Tailless Batracliia of Europe,' Raj- See. 1897, pt. i., and for 

 references to statements made bj' others upon this anatomical variation which has 

 not apparently been noted in P.fusciis. 



