1882.] DR. GADOW ON THE ANATOMY OF PTEROCLES. 319 



bankiva and in Penelope supercilinsa, whilst in our common Domestic 

 lowl It IS generally present. In the Pigeons it is often absent. 

 It present, this muscle arises with a long but narrow and fleshy 

 belly from the anterior plane of the angle between the lower end of 

 the fibula and the middle third of the tibia ; its strong tendon then 

 passes laterally over the joint and is inserted into the proximal 

 margin of the plantar tarso-metatarsal bone, near the external 

 malleolus. When contracted, the muscle bends the tarso-metatarsus 

 slightly dorsad and inwards. 



M. gastrocnemius.— 'Hhh large muscle consists in Pterocles of two 

 parts, each of which arises with two distinct heads (fig. 2) :— 



Fig. 2. 



Lateral posterior view of the gastrocnemius muscle of right side of 

 Pterocles arenarius. 



I. Median part. 



a. Cap. tibiale : from inner and anterior aspect of the head and 

 neck of the tibia, blending with the tendons of the m. femoro- 

 tibialis. 



b. Cap. femorale: from hinder aspect of the intercondyloid 

 region, and at the same time from the ligam. femoro-tibiale 

 internum. 



II. Lateral part. 



a. With a slender but distinct tendon from the intercondyloid 

 region and from the outer margin of the femur ; its belly 

 Proc. ZooL. Soc— 1882, No. XXII. 22 



