LAKYNX OF MAMMALIA. 



membrane, which extend forward and upward on eacli side of the 

 epiglottis. From the upper part of the thyroid sacculi are conti- 

 nued a pair of ' pyramidal oval ' sacculi, which occupy the sides of 

 the interspace between the epiglottis and the hyoid : and from 

 the fore part of the thyroid sac is continued the neck of the large 

 ' infundibular sac,' which expands to occupy and line the huge 

 ' bulla ' or bony cave formed by the basihyal, and of which the 

 section is shown in fig. 471. 

 Travellers in the forests of 

 tropical America testify 

 to the astounding tones 

 emitted by these far-heard 

 howling ' Monkeys. 



In most Catarrhines the 

 basihyal is expanded and 

 excavated for the reception 

 of a laryngeal sacculus, but 

 in a far inferior degree to 

 that in Mycetes. In the 

 Baboons a section of the 

 basihyal is shown at b, fig. 

 472, ' to expose the sacculus, 

 c, which is continued from 

 below the root of the epi- 

 glottis ; from this pouch the 

 sacculi continued from the 

 intercordal ventricles are 

 distinct. The back part of 

 the cricoid is traversed by 

 a medial ridge. The upper 

 and fore part of the thyroid, 

 ib. d, is produced, and supports the hyoid sac : the wings of the 

 thyroid coalesce at an obtuse angle. The crico-thyroid interspace, 

 ib. f 9 is wide. The arytenoids, ib. , resemble those of Man : 

 the santoriuian cartilages, therefrom continued, are not confluent 

 with each other apically, as in Platyrrhines. The cuneiform 

 fibro-cartilages are continued from the upper vocal cords, are 

 large, and project from the aryteno-epiglottidean folds: the free 

 border of the epiglottis is obtuse, in some species emarginate. 

 The upper vocal cords are bent ; the lower ones are rather 

 thick : above the convergence of the upper cords is the longi- 

 tudinal fissure leading to the hyoid sac. 



1 This figure is taken from the preparation. No. 1173, xx. vol. ii. p. 110. (1834). 



Larynx of Baboon. (Cynocephalus) . cccxx. 



