26 MR. F. E. BEDDARD OX THE [Jail. 14,, 



usual the corresponding set of muscles in Rana for comparison *, 

 in order to set forth those of Breviceps. There is an important 

 difference at the very beginning of this comparison. When the 

 skill covering the thigh is removed or reflected, there is removed 

 or reflected with it a thin sheet of muscle (text-fig. 6, a) which, in 

 the middle of the thigh, lies superficial to all the other muscles of 

 the thigh. Its insertion on to the knee is also the most superficial 

 insertion. There seems to be no doubt that this muscle, which 

 underlies the skin over a great part of the thigh, actually arises in 

 part at least from the skin, and is thei'ef ore perhaps to be referred 

 to the series of cutaneous muscles which have been described in 

 Rana. But there would apj^ear to be no corresponding muscle to 

 this in Rana guppyi at any rate. Posteriorly the muscle is not to 

 be distinguished for a great part of its course from the Rectus 

 internus minor. Anteriorly it does not spread on to the abdomen. 

 It seems to have nothing to do with the Rectus abdominis or 

 adjacent muscles. It is purely a thigh-muscle in its position and 

 extent. It is necessary to mention this in view of the peculiar 

 relations of the abdominal muscles to the thigh in Pipa. Although,^ 

 as already said, tliei-e is a close contiguity posteriorly with one 

 pai-t of the Rectus internus, its insertion onto the knee seems to 

 be distinct from that of the said Rectus, which muscle will be dealt 

 with presently. Apart from this muscle, Avhicli is something 

 superadded, possibly in relation to the inclusion of the thigh within 

 the contour of the body, the general plan of the femoral muscles 

 appears to be not unlike that of Rana. 



The sartorius courses obliquely over the thigh as in Rana ; its 

 insertion on to the knee is entirely fleshy. It is not a particularly 

 large muscle, being markedly smaller than the neighbouring 

 adductors. Nevertheless, its position and relations seem to fix its 

 correspondence with the sartorius of Rana, &c. When cut across- 

 the muscle is seen to lie in the hollow between its much more 

 massive neighbours. These I take to be the adductor longus and 

 (possibly) the adductor magnus respectively. In the appearance 

 of the former superficially upon the inside of the knee we have a 

 character not found in Rana. This muscle, however, is also 

 inserted on to the inner border of the femur for about the distal 

 third of that bone, and must be, as I imagine, the equivalent of 

 the adductor longus of Rana. In front of it lies, as should be the 

 case if this homology be true, the vastus intej'nus, which is a large 

 muscle. 



Between the insertions on to the knee of the two muscles last 

 dealt with a portion of the insertion of another muscle is visible, as 

 clearly shown in the accompanying figure (text-fig. Q.,Add.m.). This 

 also belongs to the adductor series, and may pei-haps be regarded 

 as the adductor magnus, the third adductor described above being 

 in that case the adductor brevis. The importance of the adductor 

 muscles in this frog is very striking. In a second specimen, the 



* I have figured these muscles in Hana guppiji in P. Z. S, 1907, p. 887, text-fig. 234.. 



