_Progne cryptoleuca_, BAIRD, Rev. Am. Birds, 1864, 277. _Hirundo
purpurea_, D’ORB. Sagra’s Cuba, Ois. 1840, 94 (excl. syn.).
_Progne purpurea_, CAB. Jour. 1856, 3.—GUNDLACH, Cab. Jour. 1861.
SP. CHAR. (No. 34,242, ♂). Color much as in _P. subis_,—rich
steel-blue, with purple or violet gloss; the wings and tail, however,
much more decidedly glossed, and with a shade of greenish. The
feathers around the anus and in the anterior portion of crissum with
dark bluish down at base, pure snowy-white in the middle, and then
blackish, passing into the usual steel-blue. The white is entirely
concealed, and its amount and purity diminish as the feathers are more
and more distant, until it fades into the usual gray median portion of
the feather. The usual concealed white patch on the sides under the
wings. Total length, 7.60; wing, 5.50; tail, 3.40; perpendicular depth
of fork, .86; difference between first and ninth primary, 2.75; length
of bill from forehead, .55; from nostril, .34; along gape, .86; width,
.58; tarsus, .53; middle toe and claw, .79; claw alone, .24; hind toe
and claw, .52; claw alone, .25.
_Female_ (17,730, Monte Verde, Cuba, May 2; C. Wright). Above
steel-blue, less glossy than in the male, and becoming lustreless dark
smoky-brown on the forehead. Head, laterally and beneath, with jugulum
and sides, uniform brownish-gray (without darker shafts or lighter
borders to feathers, as in _subis_); whole abdomen, anal region, and
crissum snowy-white, including the shafts. Wing, 5.40; tail, 2.80;
fork of tail, .70 deep.
_Young male_ (10,368, Cape Florida, May 18, 1858; G. Wurdemann).
Similar to the female, but the steel-blue above more brilliant and
continuous, the forehead and wings being nearly as lustrous as the
back; throat and jugulum mixed with steel-blue feathers, and crissum
with some feathers of steel-blue bordered with whitish. Wing. 5.40;
tail, 2.90; fork of tail, .80 deep.