950 



[R. W. H. FLOWER ON HYOMOSCIIUS AaUATICUS. [Dec. 12, 



articular surface for the corresponding arytenoid cartilage. The 

 lower border has a long pointed median prolongation. From each 

 side stands out a short triangular process for articulation with the 

 lateral processes of the thyroid ; and from the same part descends, 

 very obliquely downwards and forwards, a long, rather slender pro- 

 longation of the cartilage, which, meeting its fellow in the middle 

 line in front, completes the ring. 



Fig. 1. 



Side view of larynx of Hyoinoschus aquaticics. Nat. size. 



a. Thyroid cartilage, b. Cricoid cartilage, c. Arytenoid cartilage, d. Epi- 

 glottis, e. Thyrolival. /. Basiliyal. g. Stylohyal. 



The arytenoid cartilages (c) are flattened plates almost quadri- 

 lateral in figure, ^ inch in diameter ; the aryteno-epiglottidean 

 ligament is attached to the middle of their upper margin, the 

 thyro-arytenoid ligament (vocal cord) to the antero-inferior angle ; 

 and they are articulated to the cricoid cartilage by their posterior 

 inferior angle. 



The cavity in the interior of the larynx may be divided into two 

 parts — a direct uninterrupted passage to the trachea posteriorly, and 

 in front of this a capacious but laterally compressed pouch or diver- 

 ticulum, situated within the expanded thyroid cartilage. Owing to 



