+Rhyacophilus solitarius+, _Scl. et Salv. Nomencl._ p. 146; _Durnford, Ibis_, 1878, p. 68 (Buenos Ayres); _Barrows, Auk_, 1884, p. 315 (Entrerios, Azul); _Baird, Brew., et Ridgw. Water-B. N. A._ i. p. 278. +Totanus solitarius+, _Seebohm, Plovers_, p. 367. _Description._--Middle toe nearly as long as tarsus. Above dark olivaceous grey, with blacker markings and slightly speckled with white; upper tail-coverts blackish, barred with white; tail white with blackish bars: beneath white; sides of neck and breast streaked and barred with dusky grey; under wing-coverts blackish, barred with white: whole length 8·5 inches, wings 5·0, tail 2·1. _Female_ similar. _Hab._ Arctic America, descending south to Buenos Ayres during migration. The well-known and well-named Solitary Sandpiper arrives later than the other birds of its family in La Plata, and differs greatly from them in its habits, avoiding the wet plains and muddy margins of lagoons and marshes where they mostly congregate, and making its home at the side of a small pool well sheltered by its banks, or by trees and herbage, and with a clear margin on which it can run freely. As long as there is any water in its chosen pool, though it may be only a small puddle at the bottom of a ditch, the bird will remain by it in solitary contentment. When approached it runs rapidly along the margin, pausing at intervals to bob its head, in which habit it resembles the Tatlers or Yellowshanks, and emitting sharp little clicks of alarm. Finally, taking flight, it utters its peculiar and delightful cry, a long note thrice repeated, of so clear and penetrating a character that it seems almost too fine and bright a sound even for so wild and aerial a creature as a bird. The flight is exceedingly rapid and wild, the bird rising high and darting this way and that, uttering its piercing trisyllabic cry the whole time and finally, dashing downwards, it suddenly drops again on to the very spot from which it rose. I was once pleased and much amused to discover in a small sequestered pool in a wood, well sheltered from sight by trees and aquatic plants, a Solitary Sandpiper living in company with a Blue Bittern. The Bittern patiently watched for small fishes, and when not fishing dozed on a low branch overhanging the water; while its companion ran briskly along the margin snatching up minute insects from the water. When disturbed they rose together, the Bittern with its harsh grating scream, the Sandpiper daintily piping its fine bright notes--a wonderful contrast! Every time I visited the pool afterwards I found these two hermits, one so sedate in manner, the other so lively, living peacefully together. 406. ACTITURUS BARTRAMIUS (Wils.). (BARTRAM'S SANDPIPER.)