the Wombat and Tasmanian Devil. 171 



garoo it is largo, nnd its tendon is inserted into the base of the 

 metatarsal hones of the two inner toes. This segmentation is 

 carried a sto[) farther in Harcophihis^ and a portion of the 

 anterior tibial muscle is separated and detaches a weak tendon 

 to the second metatarsal. The tendon from the single muscle- 

 belly goes to the two metatarsals in Macropus Bennettii ; but 

 the muscle is much smaller proportionally than in the Giant 

 Kangaroo. The tendon is also double in Perameles laf/otisj 

 and is attached to the middle and inner cuneiform bones. 



The extensor digitorum longus arises from the fibula and 

 from the front of the tibia, and is inserted into the four toes 

 in the Wombat and Sarcaphi'lus. In the Phalanger and Opos- 

 sum its tendons are similarly disposed ; but in Bennett's and 

 the Giant Kangaroo it is distributed only to the third and 

 fourth toes by distinct tendons. 



The extensor brevis digitorum is present in all the marsu- 

 pials Avhich I have examined, and passes from the outer side 

 of the tarsus to be inserted into the inner pair of toes. 



The extensor hallucis in Sarcojjhilus is small and ob- 

 liquely placed between the tibialis anticus and the extensor 

 digitorum ; it is inserted into the inner toe, together with the 

 inner tendon of the short extensor. In the Wallaby it is in- 

 serted into the inner pair of toes by fine tendons. In the 

 Phalanger and the Opossum it is also inserted into two toes. 

 The Wombat possesses this musclej but it is very small, and 

 goes only into one toe. 



The gastrocnemius externus in theWombat, Giant Kangaroo, 

 SarcophilwSj and Bennett's Kangaroo arises from the sesamoid 

 bone at the back of the external condyle of the femur, and is 

 inserted into the tendo Achillis and by it into the back of the 

 OS calcis. In the Opossum the muscle arises from the outer 

 condyle of the femur. 



The gastrocnemius internus is very separate in all from the 

 external muscle ; it arises from the inner condyle and joins 

 the tendo Achillis, and is inserted in common with the last j 

 it is larger than the externus in the Wombat, but smaller in 

 Sarcopliilus. It has no sesamoid bone in any of the species 

 examined. 



The soleus has a fibular small origin in the Wombat, 

 but, as usual, has no tibial head. SarcopJiihis has also a 

 fibular soleus. The same is true in the Opossum and Pha- 

 langer, the Wallaby and Giant Kangaroo. 



The plantaris in the Opossum and Perameles is small, but 

 separate, })assing from the outer condyle to the outor side of 

 the heel ; but no plantaris exists in the Womljat. A distinct 

 small muscle in Surcophilus passes from the back of the 



12* 



