1894.] 



ANATOMY OP OENITHORHYNCHUS. 



705 



between the longus aud tbe magnus. It receives a fine branch of 

 the obturator nerve. 



Fig. 4. 



Muscles of Thigh. 



/3- 



Gracilis reflected. 



y. Adductor mass. 1. Upper one, going to femur, is longus. 2. Middle, 



slender one is brevis. 3. Lowest, going to tibia, is magnus. 

 S. Is a small portion of semi-membranosus seen from the front, 

 e. Sartorius cut through. 



Adductor magnus. — Is a thick muscle which has a comparatively 

 narrow origin from the inferior surface of ramus of ischium, its 

 origin extending as far back as tuberosity. It is inserted by its 

 base into the upper third of tibia. It may be separated into two 

 parts, anterior and posterior. Each part receives a branch from 

 the obturator nerve. The anterior portion receives in addition a 

 branch from great sciatic, which enters it on its superior surface. 

 The nerve supplies three muscles, adductor magnus, semimem- 

 branosus, and two slender branches to supposed inferior gemellus. 

 In Echidna, this muscle is inserted into linea aspera, in common 

 with brevis (Mivart, he. cit.). The muscle Coues describes as 

 adductor magnus is inserted into thigh-bone. He homologizes it 

 by its insertion into femur. Its nerve-supply, however, together 

 with the fact that in many mammals adductor magnus is inserted 

 into tibia, lead me to think that the one described above is true 

 adductor magnus. 

 Proc. Zool. Soc— 1894, No. XLVII. 47 



