236 STRUCTURE AND CLASSIFICATION OF BIRDS 



and bear much resemblance to each other, which will be 

 apparent from the illustration (fig. 115). 



The intrinsic muscles are attached to the seventh bron- 

 chial ring, which is soft and cartilaginous ; where the bronchial 

 rings change their character is a constriction of the mem- 

 brana tympaniformis ; it is, however, of equal breadth before 

 and after the change. In Podargus Cuvieri there is a further 

 approach to the purely bronchial syrinx of Steatoniis. The 



FIG. 114. SYRINX OF JEgotlic!<'x FIG. 115. SYRINX OF Batrachostomus 



(AFTER BEDDARD). (AFTER BKDDARD). 



first two bronchial rings are complete. These and the four- 

 teen following are closely applied to each other and ossified. 

 The intrinsic muscles are attached to the last of this series. 

 Mgotheles really belongs to this section of the Caprimulgi, 

 though the intrinsic muscles are attached very high up upon 

 the bronchi ; but the two rings immediately preceding the 

 attachment are complete rings. The final development of 

 the bronchial syrinx is seen in Steatoniis (see fig. 48, p. 69), 

 where all the rings in front of the attachment of the intrinsic 

 muscles low down upon the bronchi are closed and complete 

 rings, as in Crotophaga. 



The tensor patagii shows certain differences among the 

 goatsuckers. In the genera Caprimulgus, Nyctidromns, and 

 Chordeiles there is a biceps slip, absent in the rest. Of 

 these three genera the arrangement of the tendon is show r n 



