32 HISTORY OF THE 



I found them during the winter months very abundant on 

 the southwest coast of Mexico and at La Paz; and breeding in 

 numbers on the small islands in Nueees Bay, Texas, as early as 

 the first of April. The birds at such times are very noisy, and, 

 as their nesting places are approached, their hoarse notes as 

 they circle close overhead are almost deafening. Nest, a hol- 

 low, worked out in the sand, and broken shells, and lined with 

 grasses. Eggs, three; said to average 1.78x1.33; but two sets 

 collected April 12th, 1881, at Nueces Bay, only average 1.61x 

 1.20. Ground color from pale bluish green to olive buff, with 

 faint shell markings of lilac, and rather evenly and coarsely 

 spotted with different shades of brown; in form, ovate to short 

 ovate. 



Sterna hirundo LINN. 



COMMON TERN. 

 PLATE II. 



Migratory; very rare. Arrive from the middle of April to 

 first of May; returning as early as the first of September. 



B. 689. R. 686. C. 797. G. 314, 12. U. 70. 



HABITAT. Chiefly eastern temperate North America, and 

 various parts of the eastern hemisphere; breeding irregularly 

 throughout its range. 



SP. CHAK. "Adult, in summer: Pileum and nape, including upper half of 

 the lores, uniform deep black. Upper parts deep pearl gray (much the same 

 shade as in paradiscea), the border of the wings, tips of secondaries, lower part 

 of rump, upper tail coverts and greater portion of the tail pure white. Lower 

 parts pale pearl gray or grayish white (much lighter than the upper parts), be- 

 coming gradually white on the under part and sides of the head, and pure white 

 on the crissum. Outer web of lateral tail feather ash gray, darker terminally, 

 in abrupt contrast with the pure white of the inner web; outer webs of remaining 

 rectrices, except the intermedise, paler grayish. Outer web of outer primary 

 blackish slate; outer surface of other primaries light silver gray, slightly paler 

 than the back; inner webs chiefly white, with a stripe of grayish next the shaft, 

 this stripe abruptly defined on the first five quills, but growing gradually broader 

 and paler toward the fifth, and extending, near the end of the feathers, a greater 

 or less distance toward the base, but the edge itself narrowly white; five inner 

 quills pale silvery gray, the inner webs edged with white. Bill bright vermil- 

 ion, blackish terminally, except on the tornia; inside of the mouth orange ver- 

 milion; edges of eyelids black; iris very dark brown; legs and feet orange 

 vermilion, lighter than the bill; claws black. Adult, in winter: Similar, but 

 forehead, crown and anterior parts of lores white, the vertex mixed with black, 



