Ridgway American Families of Oligomyodian Passer es. 9 



e. Rectrices 12 ; bill not subulate nor acute ; tarsal envelope not 

 fused . 

 /. Heteromerous (the main artery of the thigh femoral). 



g. Tarsal envelope exaspidean (as in Oxyruncidse and Ty- 

 rannida?) ; second phalanx of middle toe partly (some 

 times wholly) coherent with outer toe or else (genus 

 Piprifes) the first phalanx wholly coherent with inner toe. 



3. Pipridae. 



gg. Tarsal envelope not exaspidean (usually pycnaspidean, 

 holaspidean or modified taxaspidean) ; second phalanx 

 of middle toe wholly free from outer toe (or else, in genus 

 Phawi circus, inner side of tarsus feathered), never 

 wholly coherent with inner toe. - 4. Cotingidse. 

 //'. Homoeomerous (the main artery of thigh sciatic). 

 g. Bill compressed, with smooth tomia ; head with a conspic 

 uous, compressed, semicircular, bilateral crest; outermost 

 primary abruptly attenuated at tip ; inner secondaries 

 abnormally broad, truncated. - - 5. Rupicolidae. 

 gg. Bill conical (finch-like), with serrated tomia ; head with 

 out crest ; outer primary and inner secondaries normal . 



6. Phytotomidae. 



ee. Rectrices 10; bill subulate, acute; tarsal envelope fused 

 (ocreate). 7. Xenicidae.* 



</</. Intrinsic muscles peculiarly expanded at lower insertion, not 

 attached to bronchial semirings, which are peculiarly modi 

 fied ; tongue penicillate. - 8. Philepittidae. 

 cc. Temporal fossse extending across occipital region of skull, the two 

 of opposite sides nearly meeting on median line. 9. Pittidae. 

 aa. Syrinx tracheal. (Tracheophonx.) 

 b. One pair of tracheo-bronchial muscles ; tarsal envelope exaspidean or 



taxaspidean ; metasternum 4-notched (except in Formicariidse). 

 c. Metasternum 4-notched ; tensor patagii brevis quasi-picarian ; nares 



holorhinal. 



d. Tarsal envelope exaspidean ; no intrinsic muscles ; sterno-tra- 



chealis not attached to processus-vocales ; palate schizogna- 



thous ; mesorhinium normal ; nostrils not conspicuously oper- 



culate. 10. Conopophagidae. 



dd. Tarsal envelope taxaspidean ; intrinsic muscles present ; sterno- 



trachealis attached to processus vocales ; palate aegithogna- 



thous (Oscine) ; mesorhinium compressed and arched, or 



expanded into a flattened oval shield ; nostrils conspicuously 



operculate. - 11. Pteroptochidae. 



cc. Metasternum 2-notched ; tensor patagii brevis normally Passerine ; 



nares schizorhinal. - - 12. Formicariidaa. 



bb. Two pairs of tracheo-bronchial muscles ; tarsal envelope endaspid- 



ean ; metasternum 2-notched. 



* See Pycraft, Ibis, Oct., 1905, 603-621, pi. 13, where the possibility of nearer relation 

 ship to Furnariidse is suggested. 



