420 LARIDZ. 
Larus cucullatus (Licht. MSS.), Reichenb. Natat. t. 23. fig. 296°; Salv. Ibis, 1865, p. 188". 
Chroicocephalus cucullatus, Licht. Nomencl. Av. Mus. Berol. p. 98’ ; Coues, Ibis, 1864, p. 888°; 
Salv. Ibis, 1866, p. 198 “. 
Chroicocephalus atricilla (nec Linn.), Sclater, P. Z. S. 1864, p. 179”. 
Pil. estiv. Supra cinerascenti-schistaceus ; collo postico et laterali et corpore subtus pure albis, hoe roseo 
induto; pileo undique nigerrimo; fascia supra- et infraoculari albo; uropygio et supracaudalibus 
lateralibus albis ; supracaudalibus reliquis et rectricibus cinereis, lateralibus fere albis; alis cinereis 
dorso concoloribus, primariis intimis et secundariis albo terminatis, primariis externis albo terminatis, 
subterminaliter nigro fasciatis, primarii primi pogonio externo nigro: rostro corallino ; palpebris coral- 
linis; pedibus sordide rubris; iride sordide grisescenti-brunnea. Long. tota circa 13:5, ale 11-5, 
caude 4°2, culm. 1°35, tarsi 1°6. 
2 haud a mari distinguendus. Long. tota circa 13-9, ale 10-7. (Descr. maris et feminw ex Champerico. 
Mus. nostr.) 
Pul. hiem. ptilosi gestive similis, sed pileo albo, nigro notato. 
Juv. Sordide cineraceus, alis brunnescentibus, torque collari albo indistincto, cinereo adumbrato; fronte et 
facie laterali albis, pileo reliquo albicante nigro marmorato, plumis nigris, albido marginatis; cauda 
pallide cinerea, terminaliter late brunneo fasciata. (Descr. femine junioris ex Chiapam. Mus, 
nostr.) 
Hab, Inver10r or Nortu America, chiefly west of the Mississippi River and east of the 
Rocky Mountains, breeding from lowa northward ®°.—Mexico 1012 ( Wagler®), west 
coast ®, lakes of Mexico (Keerl & Boucard *), city of Mexico (White 6 15), 
Zacatecas (hichardson °), Mazatlan (Grayson 38), Laguna de San Baltazar, Puebla 
(Ferrari-Perez *), Progreso, Yucatan (mus. nostr.®) ; GuatTEMALA, Pacific coast 214, 
Chiapam ° 1°, Champerico ®™ (Q. 8.); Panama (Suckley 2)—Wexst Coast oF 
SoutH America to Chile®; West Inpizs, St. Bartholomew 8. 
The present species, like the preceding, belongs to the hooded section of the genus 
Larus and has a black head in summer. It differs from LD. philadelphia in its dark 
slaty-grey mantle, and has the outer quills grey above, with a broad white tip and a 
broad black subterminal bar. | 
L. franklini breeds in marshes and is found in the interior of North America in 
summer, occurring in Central America only in the winter months. Grayson procured 
a few specimens at Mazatlan in December, but it was not common and was only 
observed during that month? *%. It is scarcely known on the eastern coasts of Mexico, 
and appears to migrate through the interior, being found on the lakes and in the 
Valley of Mexico in winter; it has, however, been met with at Progreso in Northern 
Yucatan &, 
‘Salvin noticed the species on the Pacific coast of Guatemala, where it was generally a 
short way out at sea !4, and he procured specimens at Champerico !! and on the lagoon 
of Chiapam 1°. It ranges along the west coast of South America as far as Concepcion 
in Chile ®. 
The nest is placed upon the water among the bulrushes, of which it is composed °, 
The eggs in our collection vary in form from pointed to a blunt oval ; the ground-colour 
is olive-buff, spotted and blotched with dark and light brown, and underlying pale 
