180 THE VOYAGE OF H.M.S. CHALLENGER. 



Fig. 3. Anterior and outer aspects of the right leg of the Cuscvs. 

 a 1 , and a 2 . The two heads of the peroneus longus. 



c. Fibular head of extensor brevis dicritorum for the minimus. 



o 



c'. Its tendon. 



d. Fibular head of extensor brevis digitorum for the ring digit. 



O DO 



d'. Its tendon. 



I 1 , to I*. Annular ligaments. 



b. Peroneus brevis. 

 b'. Its tendon. 



e. Extensor longus digitorum. 

 f. Tibialis anticus. 



a'. Tendon of peroneus longus. 



k 1 . Abductor ossis metatarsi minimi digiti. 



P. Abductor minimi digiti (inserted into the extensor tendon). 



¥. Abductor minimi digiti (inserted into sesamoid). 



h. Pedal portion of extensor brevis digitorum. 



g'. Tendon of extensor longus hallucis. 



1. External popliteal nerve. 



2. Anterior tibial nerve. 



3. Musculo-cutaneous nerve. 



Fig. 4. Posterior view of the right thigh of the Cuscus to show the adductor 

 muscles. 

 t. Root of the tail. 



a. Ischial tuberosity. 

 It. Obturator interims. 



c. Quadratus femoris. 

 (j 1 . Obturator externus. 



b. Femur. 



d. Adductor magnus. 



e 1 . Femoral opening in adductor brevis. 



e. Adductor brevis. 



f. Gracilis. 



1. Obturator nerve. 

 Fig. 5. Diagram of the lumbar and sacral plexuses in the Thylacine. 

 Fig. G. Diagram of the lumbo-sacral plexus in Cuscus. 



I. L. to VI. L. The six anterior primary divisions of the lumbar nerves. 



I. S. and II. S. Anterior primary divisions of the first and second sacral nerves. 



g.c. Genitocrural nerve. 



e.c. External cutaneous nerve. 



