286 H. H. WILDER, 



Processus medialis of Gaupp (No. 4) so characteristic of the 

 Anura, enter into more or less close association with the larynx. In 

 the typical forms they make a broad angle into which the larynx is 

 received, being held in position by a pair of Annulo-thyroid 

 ligaments stretching from the sides of the annulus to the points of the 

 thyroid processes. In more specialized forms the thyroid processes be- 

 come more or less consolidated with the laryngeal structures, the 

 first stage being the chondrification of the annulo-thyroid ligament 

 (Bufo). In the Aglossa the association is still more complete, the 

 thyroid processes forming a resonance box which contains the arytaenoids. 

 The form most readily comparable with the Urodeles is Alytes dbste- 

 tricans. By a glance at Fig. 37 we can recognize at once the ary- 

 taenoids below which lie the two lateral tracheal pieces united across 

 the median line on the pharyngeal^) side in such a way as to form 

 an incomplete annulus. This cartilage- complex is composed of the 

 most important Anuran elements which may be named for better de- 

 scription. The two free processes projecting posteriorly and lying on 

 the sides of the bronchi may be termed the Bronchial processes. 

 These always lie somewhat upon the cardiac side and are perhaps, 

 next to the body of the annulus, the most constant element. They 

 may serve in a preparation or diagram to indicate the cardiac or 

 ventral aspect. The loop formed by the fusion of the lateral elements 

 across the median line of the pharyngeal surface is also fairly con- 

 stant, and serves to indicate the pharyngeal or dorsal aspect. It 

 may be called the Posterior pharyngeal process. The term 

 Cardiac processes may be suggested for the remaining elements 

 which extend forward, as it were, behind ^) the arytaenoids. In many 

 other forms these make by their fusion the dorsal half of the body 

 of the annulus, but this generally involves only their posterior portion 

 leaving free cardiac processes at the anterior border of the annulus. 

 These processes are often so prolonged as to articulate or even fuse 

 with the îlrytaenoids. The arytaenoids are curious, somewhat triangular 

 structures concave upon the cardiac side and appearing as if the 

 upper outer edge were rolled over to increase the concavity. 



1) The terms "pharyngeal" and "cardiac" to designate the aspects 

 of the laryngeal and hyoid regions will prove more serviceable in 

 many cases than the more usual "dorsal" and "ventral." 



2) i. e. on the cardiac side of. The word refers to a dissection 

 from the pharyngeal side. 



