DESCRIPTION or TRE FIGURES. 



PLATE I. CHASMARIIYNCHUS. 



Fig. 1. Lower larynx of ChasmarhyncJms carunculatiis, seen from in front: natural size. 

 a. Trachea, a . Lateral muscle of trachea, h. Musculus sternotrackealis. c. Laryngeal 

 muscle. I. First, II. Second bronchial ring. 



Fig. 2. The same from behind. 



Fig. 3. The same from the side : magnified. 



I. First bronchial ring, surrounded by muscle across its whole breadth. II. Second 

 bronchial ring, the ends of which only are surrounded. 



Fig. 4. The same from the side : natural size. 

 X. Nerve of the laryngeal muscle. 



Fig. 5. Larynx of C. carnneulatus from below ; the tympanic membrane has been 

 removed. 



C. End of the muscle covering the anterior side of the larynx, which partly 

 makes tense the tympanic membrane, and partly wraps itself round the end of the first 

 and second half-rings, c. Transverse muscle lying on the anterior part of the pessulus, 

 which makes tense the tympanic membrane. 



Fig. 6. The same from below. The tympanic membrane is removed from one side, 

 but is left on the other. 



0. Pessulus. o'. Inner side of the outer boundary of the larynx. c. End of 

 the muscle which covers the anterior side of the larynx, and surrounds the anterior 

 end of the first bronchial ring, which is free from it on one side. c'. The portion 

 of this musculature which surrounds the end of the second bronchial ring. c^. Transverse 

 muscle on the anterior part of the pessulus, which serves to make tense the tympanic 

 membrane, c". Muscular fibres from the posterior portion of the larynx, which pass 

 over the edge of the larynx to the tympanic membrane, and are partly continued into 

 a muscular band c". 



Fig. 7. Diagrammatic vertical section through the trachea and bronchi. 



a. a. The last tracheal rings, li. The osseous larynx. I' , Pessulus. c. Muscles. 

 c^. The portion of muscular fibres, which pass between the lower end of the larynx, 

 and the first bronchial ring, into tlie mucous membrane, c^. Mucous membrane, d. Labium 

 of the glottis. III. Tympanic membrane. I. First bronchial ring. 



