22 MR. F. E. BEDDARD ON THE [Jan. 14,. 



of the longissimus clorsi and the pyriformis. This is true of the 

 superficial layer of the muscle. The deeper fibres are inserted 

 upon the coccyx still farther forwar-d, underlying the longissimus, 

 but I have not drawn an exact boundary line between this and 

 the ilio- coccygeal muscle. . 



When the region of the ilium is inspected from below, the ilio- 

 lumharis muscle is very plainly seen. It arises quite from the 

 tip of the ilium, where it overlaps not as might be expected the 

 coccygeo-iliacus but the glutfeus, or rather a portion of it. Owing 

 to the abbreviation of the tail the origin of the coccygeo-iliacus is 

 concealed on this aspect of the body. The ilio-lumbaris (text-fig. 

 7, A, II. I., p. 28) is a strong miiscle not bi-oken up into segments as 

 in Rana gujjpyi^, but passing straight forwards to its termination 

 on the transverse process of the third vertebra. It gives ofi" from 

 its concealed {i. e. dorsal) surface bundles of muscular fibres to the 

 transverse processes of the intervening vertebra. This muscle, as 

 it appears to me, is in some ways like that of the Pelobatidse t. 

 For instead of consisting only of detached slips as in Rana running 

 from transverse process to transverse process, there is also a massive 

 band of muscle running straight to the most anterior transverse 

 process to which the muscle is attached. This muscle is not,, 

 however, separate as in the Pelobatidfe, arising from a lower 

 (more posterior) part of the ilium ; it is indistinguishable at its 

 origin from the anterior end of the ilium from the rest of the 

 muscle. 



§ Abdominal Muscles. 



The general aspect of the rectus ahdorninis as compared with 

 that of Rana has been already described J, and need not be again 

 here referred to. While in the Common Frog according to various 

 authors the rectus abdominis does not extend far laterally, but is 

 in those regions replaced by the ohliquus externus, there is in 

 Breviceps an absolute continuity between the fibres arising from 

 the pubic symphysis in the two strong pillars already referred tO' 

 and fibres running in a nearly dorso-ventral direction on the sides 

 of the body (text-fig. 5). They form obviously one sheet which 

 may be stripped ofi:'. These fibres extend a long way towards the 

 dorsal median line. More towards the ventral median line, how- 

 ever, they become attached to the tendinous inscription, and with 

 that break are continuous with anteriorly running fibres, some of 

 which end on the sternum. Beyond the tendinous inscription 

 arises, as has been already said, the portio abdominalis of the 

 pectoralis. Beyond this again, i. e. nearer the shoulder-girdle, 

 arises a sheet of muscle which is completely hidden by the 

 pectoralis abdominalis. ^Nevertheless it lies above (ventral to) an 

 underlying sheet of muscle, which latter lies on the same plane 

 as the median region of the rectus abdominis, arising as it does 

 from it or at least from the aponeurosis covering it. This muscle 



* Beddard, P. Z. S. 1907, p. 333, text-fig. 94. 

 t Id. ihid. p. 877. % Sup^'a, p. 15. 



