292 AVES: PASSERES, — XLVI. 
the world. All are strong on the wing, insectivorous, and in our 
latitude migratory. (Lat., hirundo, swallow.) 
a. Nostrils opening directly upward, with very little membrane bordering 
inner edge. 
6. Tail forked for a distance more than half tarsus; bill very stout, curved, 
(plumage lustrous, ¢ all black). Me ME er Mik ee ee 
bb. Tail even. 
c. Outer web of outer primary without recurved hooks; (plumage lustrous). 
Perneeeee 499, 
cc. Outer web of outer primary with stiff recurved hooks, obscure in Q ; 
(plumage plain brown.) . . . . . . STELGIDOPTERYX, 503. 
aa. Nostril opening laterally, and bordered above by a broad membrane or 
overhanging scale. 
d. Tail forked for more than half its length, the outer feathers very 
narrow toward tip; no tarsal tuft. . . . .  CHELIDON, 500. 
dd. Tail forked for less than half its length. 
e. Tarsus without tuft of feathers on its lower part; (plumage lus- 
CFOUS) 5: Ce ce ie eee ~ . .« s | LAGHYCINETA, SUL: 
ee. Tarsus with a small tuft of feathare on its lower part; (plumage 
plain brownish). . . oa ee ee VEG ee 
498. PROGNE Boie. (Ipoxvn, a character in mythology, turned 
into a swallow.) 
941. P. subis (L.). PurrLe Martin. Lustrous blue-black 
throughout; Q duller, whitish and streaky below. L. 7}. W. 6. 
T. 32. N. Am., abundant. (Lat., old name of some bird.) 
499. PETROCHELIDON Cabanis. (qérpa, rock; yedudav.) 
942. P. lunifrons (Say). Cxiirr Swatitow. Lustrous steel 
blue; forehead, sides of head, throat, rump, etc., of various shades 
of chestnut; a blue spot on breast; belly whitish. L. 51. W. 44. 
T. 21. N. Am., abundant, formerly nesting in cliffs, but now 
building under the eaves of barns. (Lat., luna, moon; rons, 
forehead.) 
500. CHELIDON Forster. (yedcdav, swallow). 
943. C. erythrogaster (Boddaert). Barn Swaxiow. Lus- 
trous steel-blue, buffy below; forehead and throat deep chestnut ; 
an imperfect steel-blue collar; tail feathers with white spots. L. 7. 
W.5. T. 43. N.Am., very abundant; breeding in colonies about 
barns, etc. (Gr., red-belly.) 
501. TACHYCINETA Cabanis. (rayvxivnros, moving swiftly.) 
a. Ear coverts steel-blue; upper parts with metallic lustre. (Jridoprocne 
Coues. ) 
944. T. bicolor (Vieillot). Wuitrr-BELLIED SwaLtow. Lus- 
trous blue-green, pure white below; 9 duller. L. 64. W. 5. T. 22. 
N. Am., abundant about water ; pee handsome. 
