146 PHYSIOLOGICAL SERIES. 



unites with the ischial head and femoro-coccygeus in a 

 common insertion on the anterior surface of the tibia ex- 

 tending from the knee nearly to the ankle. The sartorius, 

 as in other Marsupials, runs directly along the anterior 

 margin of the thigh, and acts as a supplementary extensor 

 cruris. The tensor fasciae latse is absent. 0. C. 64 z/. 

 Parsons, Proc. Zool. Soc. 1898, p. 700. 



C. 203. Left knee of a Bennett's Wallaby (Macropus ruftcollis), 

 showing the rotator muscles. They consist of a popliteus 

 and pronator tibiae. The former rises from the femur, 

 external semilunar cartilage and head of the fibula, and 

 is inserted upon the posterior surface of the proximal end of 

 the tibia. The part that rises from the fibula-head forms a 

 separate slender muscle, parallel to the main portion but 

 quite distinct from it. The pronator tibiae is confluent with 

 the popliteus and forms a deeper layer of fibres that pass 

 directly between tibia and fibula. 0. C. 64 z z. 



C. 204. Right hind-foot of a Bennett's Wallaby (Macropus rufi- 

 collis), showing the long flexor tendons. Owing to the loss 

 of the 1st and reduction of the 2nd and 3rd digits, the 

 tendons of the inner side of the foot are rudimentary. The 

 tendon of the plantaris passes over the heel and near the 

 distal end of the metatarsus divides into two, which supply 

 the 4th and 5th digits. The flexor profundus (represented 

 by the flex, fibularis alone) sends tendons to all four digits. 

 Although the hallux has disappeared, the extensor longus 

 hallucis still exists and sends very fine tendons to digits 

 II. & in. The tendon of the extensor brevis quinti digiti 

 (peroneus quinti) is as large as that of the peroneus longus. 

 The peroneus brevis is absent. 0. C. 64 z g. 



C. 205. Left hind-foot of Bennett's Wallaby (Macropus ruficollis) , 

 showing the deep flexor tendons and short flexors of the 

 foot. O.C. 64 z A. 



C. 206. Gastrocnemius, soleus, and plantaris from the right hind- 

 limb of a Tree- Kangaroo (Dendrulagus bennettianus). The 



