73 
V igo2 X J Mearns, Description of a Hybrid Swallow. 
DESCRIPTION OF A HYBRID BETWEEN THE BARN 
AND CLIFF SWALLOWS. 
BY EDGAR A. MEARNS. 
In the ‘Bulletin of the Nuttall Ornithological Club,’ Yol. Ill, 
No. 3, July, 1878, page 135, Doctor Spencer Trotter described a 
hybrid between FTi rundn erythrogast er Boddaert and Petrochelidon 
lunifrons (Say). The specimen was taken at Lin wood, Delaware 
County, Pennsylvania, May 22, 1878, by C. D. Wood. “Unfortu- 
nately he [Wood] did not carefully determine its sex by dissection, 
though he believed it to have been a male.” 
On June 14, 1893, at Fort Hancock, El Paso County, Texas, 
I found a pair of swallows which were mated, and had almost com- 
pleted a nest attached to a rafter of an old building, in a situation 
too difficult for me to reach. As I recall it, the nest was similar 
to that of the Barn Swallow, having the entrance at the top. Both 
birds were shot. The male (No. 134,420, U. S. National Museum) 
was a typical Barn Swallow; but -the female (No. 134,421, U. S. 
National Museum), which was about to lay eggs, was a hybrid 
between Hirundo erythrogaster and Petrochelidon lunifrons} It 
may be described as follows: Length, 149 mm.; alar expanse, 
296; wing, 107; tail, 59; culmen (chord), 8; tarsus, 12; middle 
toe with claw, 15. 8. 1 2 The characters are, in general, intermediate 
between those of the two genera — Hirundo and Petrochelidon — 
and species. As regards the form of the bill and the form and 
1 The resident Cliff Swallow of the Rio Grande Valley is Petrochelidon 
lunifrons, not P. melanogaster , which latter occurs on the Mexican boundary 
line to the westward, from the San Luis Mountains to Nogales (monuments 65 
to t22 of the latest survey). See Proc. Biol. Soc. Washington, Vol. XIV, 
September 25, 1901, p. 177. 
2 Its mate, a typical male of Hirundo erythrogaster, measures : Length, 169 ; 
alar expanse, 308 ; wing, 114; tail, 82; culmen, 6.9; tarsus, 1 1 ; middle toe 
with claw, 16.2. 
An adult female of Petrochelidon lunifrons (No. 163,687, U. S. National 
Museum), taken at Fort Clark, Kinney County, Texas, April 28, 1898, measures : 
Length, 145; alar expanse, 300; wing, 106; tail, 53; culmen, 7.7; tarsus, 
14.5; middle toe with claw, 16. 
