1907.] ANATOMY OF THE PELOBATID^. 883 



much larger than in Leptohracliiimn (to be described presently), 

 and arises from the second tendinous intersection of the rectus 

 abdominis, and from the fascia covering that muscle for some way 

 anterior to that point. The pectoralis anterior (or pars epicorac- 

 oidalis) arises as usual from the surface of the coracoid cartilage. 

 In front lies the pars episternalis of the deltoid, which also receives 

 fibres from the small omosternum ; nothing superficial can be 

 possibly distinguished as a separate sterno-radialis such as is 

 found in Rana. The pectoralis posterior (or pars sternalis) is 

 more like that of Rana than it is like that of Megaloplirys nasnta, 

 for it extends in its origin down the whole of the bony shaft of 

 the sternum up to the expanded xiphoid plate, which line of origin 

 is of about the same length as that of the pectoralis anterior. 

 In Megalo'phrys nasuta this muscle does not reach in its line 

 of origin beyond the expanded anterior end of the bony sternum. 

 With regard to these muscles I have also examined Megaloplirys 

 montana, though they were much hardened and stuck together 

 and thus difficult to discriminate. I believe, however, that I am 

 able to assert that this species presents characters which are 

 intermediate between the two extremes already referred to. For 

 the origin of the pectoralis posterior extends some way down the 

 bony style of the sternum, in fact for about half its length. 



I could find no pectoralis cutaneus in Xenophrys monticola, and 

 in this the frog agrees with Megaloplirys nasuia. The septum 

 dividing the abdominal lymph-space from the pectoral was plain 

 enough ; but it was nowhere invaded by or connected with slips 

 of muscle arising from or near the pectoralis abdominalis. 



The considerable extension backwards of the sternum in Xeno- 

 phrys as in Megaloplirys reduces the posterior {i. e. poststernal) 

 region of the rectus abdominis muscle. In Xenophrys monticola 

 the third intermuscu.lar septum of the rectus abdominis lies on a 

 level with the end of the xiphoid cartilage of the sternum, there 

 being thus only three segments of this muscle lying behind the 

 sternum. 



The throat region of Xenophrys monticola agi'ees more closely 

 with the cori'esponding region in Rana than in the, in other 

 respects, more nearly allied Megalopihrys. The proportions 

 between the submaxillaris, the subhyoideus, and the submentalis 

 appear to me to be exactly as has been figured in Rana esculenta. 

 I may mention that the subhyoideus of both Megaloplirys nasuta * 

 and M. montana is relatively a much larger muscle. Furthermore, 

 the median raphe between the two halves of the submaxillaris 

 and subhyoideus is a mere streak. 



The ventral musculature of Leptohrachium hasseltii presents 

 considerable differences from that of its ally Xenophrys monticola, 

 and is in more than one respect much more like that of Megalo- 

 phrys. It difiers, however, from all these frogs in two very salient 

 points which are visible when the ventral integument is reflected. 



* P. Z. S. 1907, p. 340. 



