Rid gum/ — American Families of Oligomyodian Passer es. 9 



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

 fused. 



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

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

 rannidre) ; second phalanx of middle toe partly (some- 

 times wholly) coherent with outer toe or else (genus 

 Piprites) the first phalanx wholly coherent with inner toe. 



3. Pipridse. 

 (j(/. Tarsal envelope not exaspidean (usually pyenaspidean, 

 holaspidean or modified taxaspidean) ; second phalanx 

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

 Pliant Iclrcus, inner side of tarsus feathered), never 

 wholly coherent with inner toe. - 4. Cotingidas. 

 f. 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. Rupicolidse. 

 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.* 



dd. Intrinsic nuiscles peculiarly expanded at lower insertion, not 

 attached to bronchial semirings, which are peculiarly modi- 

 fied ; tongue penicillate. - - - 8. Philepittidse. 

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

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

 aa. Syrinx tracli€'al. {TracJifopJiorne.) 

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

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

 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- vocal es ; palate schizogna- 

 thous ; mesorhinium normal ; nostrils not conspicuously oper- 



culate. 10. Conopophagidae. 



(/(/. 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. Formicariidee. 



bh. 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 Furnariidte is suggested. 



