112 Mammalia. Respiratory System. 



2. The Cricoid. 



Bectorialia. In Vrms the Cricoid is almost divided by an anterior 

 cleft. 



Prohoscidia. The Cricoid extends posteriorly over the first three 

 tracheal rings. 



Artiodactyla. In the I^lh (Alces) the Cricoid is expanded behind 

 and thence produced downward so as to cross the five anterior 

 tracheal rings. 



Cete. In Phocwna the Cricoid is incomplete at the fore part. 



Sirenia. The Cricoid is larger than the Thyroid, and forms a 

 complete ring. 



3. The Epiglottis. 



Rodentia. The Epiglottis generally has a bifid apex, and at its 

 base small cartilaginous styliform bodies, separated by a triangular 

 space. 



Perissodactyla. In the Ass and Tapir the root of the Epiglottis is 

 perforated by two apertures, leading to two sacculi continued upon 

 part of the inner surface of the Thyroid. 



Cete. In Phocrena the long Epiglottis is enclosed with the Ary- 

 tenoids in a sheath of pharyngeal mucous membrane so as to form 

 therewith a long pyramidal projection, with a slightly expanded 

 apex, which is encircled, as it were grasped, by a sphincter-like 

 disposition of the muscles of the soft palate. 



Sirenia. There is no true Cartilage in the Epiglottis of Dugong. 



In-Enamellata. In the Armadillos the Epiglottis is deeply notched 

 at the apex. 



Marsupialia. The Epiglottis is remarkable for its large size and 

 generally for its emarginate apex. There is no muscle passing from 

 the Epiglottis to the tongue. In Perameles and Phascogale the sides 

 of the broad and short Epiglottis are attached to the apices of the 

 Arytenoid Cartilage. 



Monotremata. In Ornithorhyncus the apex is notched. 



4. The Arytenoids. 



Perissodactyla. In Ehinoceros the base of the Arytenoid cartilages 

 extends half way across the aperture of the Larynx, and from the 

 anterior extremities of these produced bases, the upper and lower 

 * chordae vocales' extend forward to the Thyroid cartilage and base 



