1906.] 



OF THE TRACHEOPHOXE PASSERES. 157 



truth if we reduce it to the status of a sub-family, and create, to 

 accompany it, the sub-families Pteroptochinse and Hylactinas— 

 the former of these being regarded by Sharpe (' Hand-list ') as a 

 Family, and the latter as a genus only thereof. 



The essential feature of the Conopophagidie is the 4-notched 

 sternal plate, and the most primitive member of the family is 

 Gonopophaya. In the peculiar character of the sternum (p. U/) 

 this family is unique among the Passei-es. _ _ 



The Furnariine forms need careful reyision. The composition 

 of this family roughly corresponds to the Dendrocolaptidte of 

 Dr. Sharpe minus the Dendrocolaptina?, which, it seems to me, 

 should be regarded as a separate Family. 



As touching the Xenicidje, I haye recently elsewhere (8) con- 

 tended that this Family is more or less nearly related to the 

 Synallaxidffi, and this largely, but not entirely, on account of 

 osteoloc^ical characters. More primitiye in some respects than 

 this Family, they differ chiefly in the form of the syrmx, which is 

 tracheo-bronchial, and therefore the Xenicidse would appear to be 

 at the bottom of the tracheophone stem, the members of which 

 split up into holorhinal and schizorhinal types. 



The scutellation of the podotheca, largely used in Sclater and 

 Salv-in's classification of the Group (10), cannot be rehed on as a 

 o-uide to the closer bonds of affinity. Thus, in the Conopophagidse, 

 Ijonopophaga is exaspidean, like the Tyi^annida? and Piprid^e ; 

 Pteroptochus is taxaspidean,like the Formicariida^ and Philepittidse, 

 while the Dendrocolaptina? and Synallaxinss are endaspidean. 



In the matter of pterylosis all the Tracheophonete haye a long 

 10th remex and a vestige of the Uth, and all have a more or less 

 saddle-shaped expansion to the pt. spinaHs, the tract behind this 

 being feebly developed. 



The curious form of the nostrils of Xenicus and the remarkable 

 structure of the external ear I have already described at length 

 (8). But little attention has ever been paid to this aperture, 

 and it is probable that a careful study of the form of the external 

 ear will be rewarded by interesting results. 



The external nares in Scytalojyus and Couopophaga are covered 

 by a leaf -shaped operculum. • 



The deltokleus lomjics and brevis— muscles of the shoulder-girdle— 

 are, as Dr. Mitchell has shown, of considerable value as factors m 

 classification. In the paper on Acanthidositta, to which I haye 

 several times referred here, I have shown that these muscles, in 

 this genus, have preserved their primitive character to a very 

 unusual degree : the longus portion being two-headed, the second 

 head being attached to the os humero-scajndare and forming with 

 the claviculo-scapular head a large and powerful muscle inserted 

 into the ectepicondylar process of the humerus by a short tendon. 

 In such Tracheophonese as I have been enabled so far to examine 

 in this respect, I find the more normal, specialised, condition to 

 obtain. Thus in Scytalopm and ConopopJiaga and in Formicivora 

 the longus portion has lost the second head, though in Conopo- 



