460 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. 56. 



1907). This was in midwinter. On the south Santa Rosa, a 

 relatively low, flat-topped island, the nests lay so thickly on the 

 ground, and the eggs were so inconspicuous among the small stones, 

 that, despite great watchfulness, one could not walk about without 

 crushing the eggs. The young birds, however, stood in little danger, 

 since even in the fledgling stage they were wary and exceedingly 

 active ; they would run quickly away even to a distance and become 

 almost invisible beside a small bit of gravel. No other birds of the 

 islands were observed to be either so active or so successful in con- 

 cealment. In the stomachs of two specimens examined there were 

 found chiefly small fishes, the common anchobetas, Engraulis ringens 

 Jenyns. 



Another tern, very similar to the terrecle in markings, though 

 greatly different in size, is the little S. lorata Philippi and Landbeck, 

 the " Churi-Churi " of Paracas Bay, where it was seen most abun- 

 dantly. 



LAROSTERNA INCA (Lesson). 

 THE INCA TERN OR "ZARCILLO." 



One of the most fascinating birds of the coast is the beautiful Inca 

 tern, Larostema inca (Lesson), known in Peru generally as the "zar- 

 cillo." At Eten they call it "aromito. " Although noted as far 

 north as Lobos de Afuera, it was observed in greatest abundance in 

 the southern region. 



The body color is almost uniformly a dull dark blue, but the head 

 and the outer parts of the wings are a little darker, while the under 

 side of the wings is lighter. From the lower part of the base of the 

 upper jaw a pure white band, or ''moustache" extends backward, 

 below the eye and just above the yellow fleshy flaps, to the region 

 of the ear; there it ends with a half-dozen long slender little plumes 

 that emerge from the feathers, and curve backward, downward, and 

 outward in graceful manner. "The bird with the white earrings" 

 a visitor termed it. 



It is altogether a most pleasing bird in its grace of form and move- 

 ment, as well as in its strikingly neat and even dandified appearance. 

 The soft dark blue of the plumage is effectively varied by the crimson 

 of biU and feet, the white margin of the wings, the yellow flaps at 

 the gape of jaws, and the showy "earrings." 



In flight it apparently dehghts in sharp curves, quick reverses of 

 direction, or sudden drop with webbed feet outspread. The forked 

 taU presents a variety of forms in these maneuvers, now widespread 

 and fan-shaped losing all trace of the fork, now closed in swaUow-tail 

 effect, or, again, so snugly closed as to obscure the forked form 

 entirely. 



The Inca terns have a most inquisitive habit. Even when there was 

 no probability of being near to the nests, they would circle rapidly 



