ATTICORA. 309 
in having the toes more deeply cleft—the basal joint of the median 
_being free at its extremity on the outer side, instead of being adhe- 
rent to the middle, or even the end of the middle joint. From Pelro- 
chelidon it differs in the longer tarsi, which equal the middle toe 
and half its claw, not the middle toe alone ; less completely feathered 
tarsi at upper end; and in wanting the bristles in the chin and at 
base of bill above, which are soft and smooth. While the nostrils 
in Petrochelidon appear in the dried skin to be entirely without 
membrane, in Pygochelidon they are bordered behind and internally 
for a short distance, without, however, being overhung. 
Synopsis of Species. 
Above and on erissum uniform lustrous blue-black. Beneath 
white; the feathers of chin and throat dark plumbeous at 
base. 
Breast with a black pectoral band. Feathers of back 
scarcely white towards their middle portion. Cris- 
sum entirely black . - : : 5 6 . melanoleuca. - 
Breast without pectoral band. Feathers of’upper back 
white in middle. Crissum with all feathers entirely 
black . ° : 
‘ ; : : - cyanoleuca. 
(Var. montana with larger bill.) 
Breast without band. Crissum white towards anus; long 
feathers only black, and towards their tips. Feathers 
of upper part of back ash-colored, not white in middle patagonica. 
Above and on crissum greenish-black. Beneath dark ashy ; the 
feathers of chin and throat plumbeous at base. 
Feathers of upper part of back cinereous, not whitish in 
the middle . . c 
5 < A . murina. 
Atticora cyanoleuca. 
Hirundo cyanoleuca, Viet. Nouv. Dict. XIV, 549, and Encycl. Méth. 
1823, 521 (based on Golondrina de la timoneles negros, AZARA, Apunt. 
Pajaros Par. II, 1805, 508).—Atticora c. Cas. Mus. Hein. 1850, 47. 
—Borm. Uebers. II, 1857, 146.—Is. La Plata Reise, II, 1861, 479 
(very common in the La Plata country; nests under eaves and 
roofs of houses). 
Hirundo melampyga, Licut. Verz. 1823, 57 (Bahia). 
Hirundo minuta, Max. Beit. III, 369.—Tremm. Pl. Col. 209, fig. 1. 
Hab. La Plata basin ? Brazil. 
(No. 35,050.) Above and on sides of head and reck to line of gape, steel 
blue, including tail- and lesser wing coverts, as well as a patch on side of 
breast; wings and tail feathers dark blackish-brown, with faint gloss. 
Feathers of hind neck and interscapulum with concealed white in their middle 
portion. Beneath white, all the feathers blackish plumbeous at the base, ex- 
