3io 



ELEMENTAR Y ANA TOMY. 



[LESS. 



This muscle, even in Mammals, may be blended with the 

 temporal, as is the case in the Two-toed Ant-eater. 



The temporal muscle of man is but very poorly developed 

 compared with what we find in many other forms, such as the 

 Tiger. It may, on the contrary, be less developed relatively 

 than in man, as in the Hare. It may be divided into three 

 or four portions, as in the Fowl and Goose. 



FIG. 282. SUPERFICIAL MUSCLES OF RIGHT SIDE OF MENOPOMA. 



A A, adductor arcuum ; B, biceps; CA, constrictor arcuum ; CF, constrictor 

 faucium ; D, deltoid ; D l , digastric ; EL, extensor longus ; ExO, external 

 oblique; LA, levator arcuum; LD, latissimus dorsi ; M, masseter; MH 1 , 

 anterior pai. of mylo-hyoid ; MH' 2 , posterior part of mylo-hyoid; S, sub- 

 clavius ; SL, supinator longus ; T, trapezius ; T, triceps ; U, ulnaris. 



The pterygoid muscles of man are essentially similar to 

 the same parts in the whole of his class ; but these muscles 

 may be indistinguishably united into one, as in Menopoma, 

 or even with the temporal, as in Menobranchus (Fig. 286). 

 They may be very large, as in venomous Serpents. 



1 6. The ORBITAL MUSCLES of man present a condition 

 which is normal, these parts exhibiting a remarkable con- 

 stancy in vertebrate animals. 



Such parts, however, may be entirely wanting even in 



