368 



COMPARATIVE ANATOMY 



by a thin arytenoid cartilage on either side of the glottis as well 

 as by a ring-shaped cricoid cartilage, from which delicate processes 



Sp 



SR 



FIG, 274. CARTILAGINOUS SKELETON OF THE LARYNGO-TKACHEAL CHAMBER OF 

 Rana esculenta. A, from above ; B, from the side. 



Ca, Ca, arytenoid cartilages; C.I 1 C.I 4 , cricoid cartilage; P, plate-like ventral 

 part of the cricoid; Sp, pointed process of the cricoid; 8R, glottis; ***, 

 three conical prominences of the arytenoids. 



pass backwards to the roots of the lungs (Fig. 274). Vocal cords 

 are developed in the Anura only, each being attached to the inner 

 concave surface of the corresponding arytenoid. 



The intrinsic laryngeal muscles of Amphibians, which are sup- 



FIG. 275. LARYNX OF Phyllodactylu* europceus. (A, skeleton, and B, 

 musculature of larynx.) 



Ar, arytenoids ; Cc, cricoid ; D, dilator ; Oe, entoglossal ; S, anterior median 

 process of cricoid ; S l , sphincter ; T, trachea. 



plied by a branch of the vagus and are important in respiration 

 (as well as in the production of the voice in Anura), include a 



