ELEMENTAR Y ANA TOMY. 



[LESS. 



transfer sales. It is a constant muscle in man's class, varying 

 in size with the dimension of the atlantic transverse process, 

 and therefore being large in the Carnivora. 



The pharyngeal muscles of man are structures which are 

 exceptional amongst Vertebrates, as they are developed in 

 the highest class alone. 



In Birds, Reptiles, Batrachians, and Fishes there are no 

 proper constrictors of the pharynx, but only fibres which are 

 quite homologous with those of the oesophagus. 



FIG. 287. SUPERFICIAL MUSCLES OF EXTENSOR SIDE OF LEG AND OF FARTS 



OF TRUNK AND TAIL OF MENOPOMA. 

 ES, erector spinae directly continued into dorsal half of tail ; ELD, extensor 



longus digitorum pedis ; FC, femoro-caudal ; GMx, probably rectus femoris ; 



/, muscle resembling iliacus ; ILC, ilio-caudal ; IP, il'o-peroneal ; RF, part 



of great extensor of thigh ; SM and ST, muscles like the semi-membranosus 



and semi-tendinosus. 



These fibres may, however, form a well-developed pha- 

 ryngeal sphincter, as in Fishes, and serve for moving those 

 " throat-jaws," the pharyngeal bones, which exist in so many 

 of the lowest Vertebrate class. 



Much variety in form and in the details of attachment may, 

 however, exist in the Mammalian pharyngeal constrictors, 

 and we may find a greater degree of complexity than in man. 



