624 MU. p. OHALMERS MITOHELI, ON THE [June 16, 



which is separate and muscular in Palamedea, separate and 

 tendinous in Qallus. 



Ttmporalis. — The superficial portion of this muscle is very large 

 and inseparable into layers ; it arises from the whole temporal fossa, 

 and from the external and internal surfaces of the mid-temporal 

 process ; it runs forwards and downwards under the quadrato- 

 maxillary bar to the outer upper surface of the lower jaw ; internal 

 to this, and arising from the deeper region of the temporal fossa, 

 is a strongly marked pyramidal muscle, which ends in a stout 

 tendon inserted to the inner surface of the lower jaw. A still 

 deeper portion runs across from the forward process of the 

 quadrate to the inner side of the ramus. Lastly, a wide band of 

 muscle bridges the narrow interval between the inner edge of the 

 forward process of the quadrate and the wall of the orbit behind 

 the optic foramen. 



Pterygoid. — A superficial portion, similar to that found in Ducks 

 and Geese runs from the ventral, posterior end of the lower jaw to 

 the palatal membrane. It is not so tendinous as in the Ducks and 

 Geese. The deeper portion of the j)terygoid is an almost continu- 

 ous mass of muscle, inseparable into regions, from the pterygo- 

 palatine area to the lower jaw. 



Muscles of tub Leg. 

 Variations in the Gondilions of the Ambiens. 



In the musculature of the leg there are several points (illus- 

 trated by figure 3, p. 625, and figure 4, p. 626) to which I wish 

 to refer. As Garrod showed, the four muscles which he called 

 A, B, X, and Y, the femoro-caudal and its accessory, the semiten- 

 dinosus and its accessory, are all present. The interconnections 

 between the muscles at the back of the knee differ so in birds that a 

 description of their exact condition in Oinsthocomiis may be placed 

 on record, although I have not yet sufficient material to make 

 comparisons of any value. 



The adductors have no insertion to the tibia, but send a strong 

 slip to the middle head of the gastrocnemius. The semimem- 

 branosus, the most posterior of the thigh-muscles, runs straight in 

 to the tibia, unconnected with the tendon of the semitendinosus. 

 The accessory semitendinosus is very broad and strong, but does 

 not nearly reach the tibia, being separated from that by the middle 

 head of the gastrocnemius. The semitendinosus, after being 

 joined by its accessory, sends in one fibrous slip to the tibia, 

 proximal to that of the semimembranosus ; while the greater mass 

 of the muscle ends in a strong tendon, which runs down alongside 

 and soon fuses with the middle head of the gastrocnemius, before 

 that reaches the tibial head. 



The condition of the amhiens muscle is still more interesting. 

 Garrod (see paper referred to above) examined the legs of three 

 specimens of Ojuisihocomus. In all cases he found the ambiens 

 small, but normal, above the thigh. In five of the six legs it was 



