48 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. XIV. 



base of the marsupial bone and dorsad along the ramus of the ischium 

 to the semimembranosus. Insertion on most of the length of the caudal 

 surface of the femur from the insertion of the adductor brevis near the 

 lesser trochanter to the insertion of the longus at the base of the inner 

 condyle. This muscle lies between the brevis and the longus and its 

 exposed surface lies next to the pectineus. At its origin it lies entad of the 

 longus which parallels it distad. 



Adductor brevis. Origin from the side of the dorsal half of the ascend- 

 ing ramus of the ischium to the side and front of the tuberosity of the 

 ischium and for a slight distance craniad. Insertion on the distal caudal 

 edge of the great trochanter of the femur caudo-entad of the insertion of 

 the gluteus maximus and thence transversely of the femur to a point 

 slightly distad of the lesser trochanter. The outer surface of this short 

 broad muscle is wholly covered by the gracilis, the semimembranosus, 

 and the other adductors. 



Caudofemoralis. Origin by a broad tendinous aponeurosis from the 

 fascia covering the multifidae and somewhat attached to the articular 

 processes of the third caudal vertebra. The insertion is double, one 

 slender slip inserting by a short tendon on the inner edge of the inner 

 condyle of the femur between the adductor longus and the gastrocnemius . 

 The other division of the muscle passes on the opposite side of the 

 adductor longus and inserts by several fasciculi on the caudal surface of 

 the distal fourth of the shaft of the femur. Near its insertion it is 

 slightly connected with the adductor. This muscle, which is not present 

 in the didelphids, is well developed, but shows some variation even in 

 the small number of specimens dissected. At its origin it lies immediately 

 entad of the femorococcygeus and slightly distad is separated from it by 

 the great sciatic nerve. It passes transversely to the bases of the ad- 

 ductors, but is free from the femur to its insertion. Its ental surface 

 near its origin has relation with the caudal muscles, the quadratus 

 femoris, and the obturator internus as it passes distad just craniad of the 

 biceps femoris. Its presence is reported in Notoryctes, Phalanger, Thy- 

 lacinus, Myrmecobius, and Dasyurus. 



Pectineus. Origin from the side of the pubis at the anterior base of 

 the marsupial bone. Insertion on the inner surface of the femur slightly 

 proximad of the middle. A short thick muscle lying ectad of the 

 insertion of the psoas major. 



Femoro-coccygeus. Origin aponeurotic from tendinous fascia be- 

 tween the cephalic and caudal articular processes of the third caudal 

 vertebra. Insertion by several fasciculi on the distal third of the caudo- 

 lateral surface of the femur. It is separate from the gluteus maximus 

 except near the insertion where the fascia join. It has a slight twist 



