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. 
&. Tail forked for a distance more than half tarsus; bill very stout, curved, 
(plumage lustrous, f all black). . . .. .». . . Proene, 498. 
6b. Tail even. 
c. Outer web of outer primary without recurved hooks; (plumage lustrous). 
PETROCHELIDON, 499. 
cc. Outer web of outer primary with stiff recurved hooks, obscure in 9; 
(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. . . . » « Hrrunpo, 500. 
dd. Tail forked for less than half its length. 
ce. Tarsus without tuft of feathers on its lower part; (plumage lus- 
trous). . . . « «© « + » . Tacnycrneta, 501. 
ee. Tarsus with a scnall tuft ‘of feathers on its lower part; (plumage 
plain brownish). . . oo + + « «© « « Ruaparta, 502. 
498. PROGNE Boie. (Ipoxvn, a character in mythology, turned 
into a swallow, ) 
941. P. subis (L.). Purpre Martin. Lustrous blue-black 
throughout; 9 duller, whitish and streaky below. L. 74. W. 6. 
T. 3}. N.Am., abundant. (Lat., old name of some bird.) 
499. PETROCHELIDON Cabanis. (mérpa, rock; yedsddv.) 
942. P. lunifrons (Say). Ciirr Swattow. Lustrous steel 
blue; forehead, sides of head, throat, rump, etc., of various shades 
of chestnut; a blue spot on breast; belly whitish. L. 5}. W. 44. 
T. 24. N. Am., abundant, formerly nesting in cliffs, but now 
building under the eaves of barns. (Lat., luna, moon; frons, 
forehead.) 
500. HIRUNDO Linneus. (Lat., swallow.) 
943. H. erythrogaster Boddaert. Barn Swatitow.  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. 4}. N.Am., very abundant; breeding in colonies about 
barns, etc. (Gr., red-belly.) 
501. TACHYCINETA Cabanis. (rayvxivyros, moving swiftly.) 
«. Ear coverts steel-blue; upper parts with metallic lustre. (Jridoprocne 
Coues. ) 
944. T. bicolor (Vieillot). Wauirs-sELLiep Swatiow. Lus- 
trous blue-green, pure white below; 9 duller. L. 6}. W. 5. T. 22. 
N. Am., abundant about water; very handsome, 
