108 BULLETIN 50, UNITED STATES NATIONAL MUSEUM. 



From the nature of the characters upon which the above arrange- 

 ment is based, it is obvious that the classification presented can be 

 considered merely tentative and that a more careful study of the 

 subject is required. It is true that characters additional to the above 

 are given in Count Salvadori's "key," but they do not contrast and 

 therefore only serve to obscure or complicate the diagnoses. 



KEY TO THE AMERICAN GENERA OF PSITTACTD-ffi: .<* 



a. Tail distinctly graduated, with rectrices narrowing or tapering terminally, or else 

 (Psittamla) the middle rectrices distinctly acuminate, the others subacuminate. 

 6. Tail more (usually much more) than half as long as wing, distinctly graduated, 

 or else middle rectrices distinctly longer than the rest and outermost primary 

 with tip not attenuated; sexes alike in coloration; furcula present; larger 

 (length more — usually very much more — than 150 mm.), 

 c. More than orbital region and chin naked. 

 d. Larger (length more, usually very much more, than 380 mm.); bill more 

 compressed, the width of maxilla at base equal to not more (usually less) 

 than half the length of culmen, the greatest width of mandible less than 

 length of gonys; the maxillary unguis thicker and more obtuse or else 

 (Anodarrhynchus, part) distinctly compressed, or (Ognorrhynchus) a broad 

 post-mandibular naked area, and lores feathered; tail not shorter (usually 

 longer) than wing; cheeks partly naked. 

 e. Tip of mandible extremely broad, its width equal to more than half the 

 length of gonys; loral and suborbital regions normally feathered, a 

 broad feathered space separating the naked orbital space from that 

 behind base of mandible; unicolored (wholly blue or bluish). 



Anodorhynchus (p. 117). 

 ee. Tip of mandible much narrower, its width equal to not more (usually 

 less) than one-third the length of gonys; loral and suborbital regions 

 naked or else (Ognorhynchus) maxillary unguis slender and acute ter- 

 minally, chisel-like tip to mandible very short, and forehead, suborbital 

 region, and auricular region yellow; particolored (plumage with red, 

 yellow, or green, besides blue, the latter sometimes absent). 

 /. Loral and suborbital regions naked; maxillary unguis not attenuated 

 nor acute; tip of mandible more produced; forehead and auricular 

 region not yellow. 

 g. Bill much larger, the culmen much longer than outer hind toe without 

 claw (usually longer than outer front toe without claw, sometimes 

 longer than tarsus and outer front toe without claw); anterior lateral 

 outline of cere more or less strongly sinuated (convex above, con- 

 cave below); excision of mandibular tomium relatively shallow 

 and broad; corrugations of palatal surface of maxillary unguis 

 distinct; sides of forehead feathered Ara (p. 119). 



o The only American genus of the group not examined in the present connection is 

 Cyanopsitta Bonaparte (Eev. et Mag. de Zool., (2) vi, 1854, 149; type, Sittace spixii 

 Wagler)— the name emended to Cyanopsittacus by Salvador! (Oat. Birds Brit. Mus., 

 xx, 1891, 150). This genus has usually been placed next to Anodwhynchus, probably 

 on account of ite wholly bluish coloration; but judging from descriptions and colored 

 figures it seems not to be closely related to the latter, though its real relationships can 

 be determined only by examination and comparison with other genera. It is prob- 

 ably most nearly related to some of the smaller forms here referred to Ara, or possibly 

 to Orthopsittaca. 



