408 LARIDA. 
latter part of March, when it congregated on the beach in large numbers, and in a 
short time disappeared for its breeding-grounds®. Mr. Nelson did not find the 
species on the Tres Marias Islands®. In winter it extends its range along the western 
coast of South America to Peru and Chile +. 
An egg taken by Captain Stone at Guaymas was white with a pinkish tinge; the 
markings were quite bold and distinct, and were of a deep black and burnt-sienna 
colour, with subdued shell-markings of lavender-grey ”. 
| (7. Sterna anzstheta. 
L’ Hirondelle de Mer de V’Isle de Panay, Sonn, Voy. Nouv. Guin. p. 125, pl. 84’. 
Sterna anestheta, Scop. Del. Faun. et Flor. Insubr. ii. p. 927; Baird, Brewer, & Ridgway, Hist. 
N. Amer. Birds, ii. p. 316°; Zeledon, Cat. Aves Costa Rica, 1887, p. 133*; A.O. U. Check-l. 
N. Amer. Birds, 2nd ed. p. 26°; Saunders, Cat. Birds Brit. Mus. xxv. p. 101°; Oates, Cat. 
Eggs Brit. Mus. i. p. 1907. 
Haliplana panaya (Lath.), Salv. Ibis, 1864, p. 381°; Coues, Ibis, 1864, p. 391°. 
Haliplana panayensis (Gm.), Salv. Ibis, 1866, p. 199*°. 
Onychoprion panayensis, Scl. & Salv. P. Z.S. 1871, p. 572"; Zeledon, Cat. Aves Costa Rica, 1882, 
p. 36 ». 
Haliplana discolor, Coues, Ibis, 1864, p. 392, note’. 
Ptil. estiv. Supra fuliginoso-brunnea, schistaceo lavata; interscapulio canescentiore ; pileo nuchaque niger- 
rimis; fronte angusta et supercilio brevi pure albis; loris et fascia lata oculari nigris, pileum nigrum 
lateralem conjungentibus ; collo postico celato, faciei et colli lateribus ‘et corpore subtus toto pure albis ; 
alis dorso concoloribus ; tectricibus primariorum et primariis nigricantibus, vix cinereo lavatis, et intus 
cuneatim albis; uropygio et cauda clarius schistaceis, rectricibus intus et basin versus albis, externis 
plerumque albis apicem versus cinerascentibus, rectrice extima alba, vix subterminaliter cinerascente : 
rostro et pedibus nigris; iride saturate brunnea. Long. tota circa 15:0, ale 10°1, caude 2°8, rectrice 
extima 6°5, culm. 1:55, tarsi 0°85. (Descr. maris adulti ex Lighthouse Reef. Mus. nostr.) 
mari similis. Long. tota circa 14-8, ale 10°45. (Descr. femine adults ex Southern Water Cay. Mus. 
nostr.) 
Ptil. hiem. ptilosi estive similis, sed pileo albo maculato distinguenda. 
Juv. adultis hiemalibus similis, sed pileo toto nuchaque nigro striatis, notei plumis albido marginatis ; 
tectricibus alarum minimis nigricantibus; primariis et rectricibus saturatioribus, intus magis restrinte 
albidioribus: subtus pure alba. (Deser. av. juv. ex Florida. Mus. nostr.) 
Hab. Nortn America, casual in Florida®.—Britiso Honpuras, Cays of Belize coast !°, 
Lighthouse Reef ®, Saddle Cay78, Curlew Cay’, Southern Water Cay® (0. 8.) ; 
Costa Rica (Zeledon 4 12).—West InpiEs °.—Coasts anp IsLanps of South Atlantic 6 
Indian, and Pacific Oceans °. 
Owing to their style of coloration, the Sooty Terns have been often considered to 
be generically distinct from the typical species of the genus Sterna, but Mr. Howard 
Saunders (¢. c. p. 110) has been unable to find any structural characters to warrant 
their separation. 
The present species is easily recognized by its dark smoky-brown upper plumage and 
white breast, this latter character being present in the young birds also. It occurs 
occasionally in Florida, but breeds in Central America, as Salvin procured the eggs on 
