Account of Observed Forms of Larynx. 35 



unite the ends of them, as in Xenops. The muscles of the processus tocalis resemble 

 those of Furnarius. 



Genus Tinador Pr. M. The base of the tracheal larynx is formed, on either side, 

 by the first and second bronchial half-rings, and in the middle by the lowest ring of 

 the trachea, which is connected with it; this is complete posteriorly, but is cleft 

 anteriorly, so that it is, in front, like a bronchial half-ring. In the membranous 

 flattened wall of the tracheal vocal membrane there are eight extremely fine anterior and 

 posterior half-rings. The bony piece has its base resting on the first bronchial half- ring, 

 and the last tracheal ring. The muscles of it are double, as in Furnarius and Cinclodes. 



Pr. Max was rio-ht in thinking that this bird would connect the Mfiotherae with 

 the Bendrocolaptinae. 



Xenoris. The base of the tracheal organ of voice is formed of the first three 

 bronchial half-rings, which are closely connected together, and the last complete tracheal 

 rino-. The osseous pieces are as usual attached to the bronchi, and are very broad ; their 

 muscles are attached close to their tips, whence arise the m.useidi sternotracheales. The 

 membranous portion of the trachea is longer than it is broad ; it contains, however, only 

 three extremely fine half-rings, which are embedded in the membranous wall, and never 

 reach to the sides. I examined Xenops rutilus Licht. 



Synallaxis Vieill. The osseous pieces are as usual, and are attached to the first 

 and second bronchial half-rings. The base of the tracheal larynx also consists of three 

 closely approximated and complete tracheal rings. The membranous portion of the 

 trachea is broader than it is long, and seems to contain, at the most, a trace of 

 half-rings ; at least, in Sj/nallaxis rn-ficaucla Spix., I only noticed a single minute 

 band, in the lower part of the membrane. The muscles of these pieces are attached 

 to their median part. 



Dendrocolaptes Herm. The base of the tracheal larynx forms two halves, one 

 anterior and one posterior, which touch one another ; the commencement of the 

 bronchi, which are greatly enlarged, consist of the large first and second bronchial 

 rino-s. On this base the pyramids or processus vocales are placed, which in this genus 

 are remarkable from their sending out anteriorly and posteriorly a processus miiseidaris, 

 which forms, as it were, a handle for the attachment of the anterior and posterior vocal 

 muscles, which arise from the trachea. The vocal membrane of the trachea contains six 

 to seven half-rings. The handles on the processus vocales resemble those in the sub- 

 genera of the Bendrocolaptinae. I examined B. cayennensis Licht., and B. tenuirostris 

 Mus. Berol. 



F 2 



