III. Sittacinæ. Head plain. Tail long, or lengthened, wedge-shaped or graduated.
IV. Psittacinæ. Head plain. Tail short or moderate, straight or rounded.
V. Trichoglossinæ. Tip of tongue papillose. Bill compressed; tip of maxilla internally smooth, not crenate; gonys obliquely ascending.
Of these, Nos. III and IV alone are represented in the New World, and only the Sittacinæ occur in the United States, with one species.
Subfamily SITTACINÆ.
The lengthened cuneate tail, as already stated, distinguishes this group from the American Psittacinæ with short, square, or rounded tail. The genera are distinguished as follows:—
Sittace. Culmen flattened. Face naked, except in S. pachyrhyncha. Tail as long as or longer than wings.
Conurus. Culmen rounded. Face entirely feathered, except a curve around the eye. Tail shorter than wings.
Of the genus Sittace, which embraces eighteen species, two come sufficiently near to the southern borders of the United States to render it not impossible that they may yet be found to cross the border. Of one of these, indeed, (S. pachyrhyncha,) there is a specimen in the Museum of the Philadelphia Academy of Natural Sciences, presented by J. W. Audubon as shot on the Rio Grande of Texas; and another (S. militaris) is common at Mazatlan, and perhaps even at Guaymas. There is considerable reason for doubt as to the authenticity of the alleged locality of the S. pachyrhyncha, but for the
purpose of identification, should either species present itself, we give diagnoses in the accompanying foot-note.[137]