LARUS. 425 
In the interior of North America this species breeds in many places in large numbers. 
It feeds on fish and also on locusts, catching the latter in the air. 
Two eggs in the British Museum are very different from each other. One is of 
a regular oval form and has an olive-buff ground, sparingly marked, except at the 
larger end, where there are huge confluent blotches forming an irregular zone, with 
spots and specks of deep chocolate-brown; the underlying pale purple markings are 
few and inconspicuous. The second specimen is a pointed oval and has a light buff 
ground, boldly marked all over with spots and blotches of blackish-brown. The 
underlying markings on this egg are numerous, large, and conspicuous”. 
7. Larus californicus. 
Larus californicus, Lawr. Ann. Lye. N.Y. vi.p. 79"; Bull. U. S. Nat. Mus. no. 4, p. 51°; Sumichr. 
La Nat. v. p. 234°; Herrera, La Nat. (2) i. pp. 188%, 329 >; Baird, Brewer, & Ridgway, 
Water-Birds N. Amer. ii. p. 242°; Ferrari-Perez, Pr. U. S. Nat. Mus. ix. p. 179°; 
A. O. U. Check-l. N. Amer. Birds, 2nd ed. p. 19°; Saunders, Cat. Birds Brit. Mus. xxv. 
p. 276°; Oates, Cat. Eggs Brit. Mus. i. p. 217, t. 18. fig. 2°. 
L. delawarensi similis, sed major, interscapulio saturatiore schistaceo; scapularibus et secundariis latius albo 
terminatis, albedine primariorum extimorum latius extensa: rostro flavo, macula vel fascia subterminali 
seepius obsoleta, macula anteapicali intense coccinea ; pedibus virescentibus; annulo periophthalmico 
miniato ; iride corylina. Long. tota circa 18-5, ale 15:2, caudex 5:9, culm. 1:9, tarsi 2°3. 
2 ad. mari similis, sed minor. Long. tota circa 18-0, alee 15-2. (Descr. maris et femine ex Ventura, 
California. Mus. nostr.) 
Ptil. hiem. ptilosi estive similis, sed pileo et collo summo grisescenti-brunneo striolatis: rostro grisescenti- 
albo, apice flavicanti-albo, nigro subterminaliter vittato ; pedibus sordide virescenti-albis ; iride corylina. 
Hab. Wausvern Nortu America, chiefly in the interior, from Alaska southwards °, once 
as far east as Kansas?,— W. Mexico®, Valley of Mexico (ferrera*°), Vera 
Cruz, Alvarado (Ferrari-Perez’), Gulf of Tehuantepec on the coasts, San Mateo 
(Sumichrast ? °). 
The present species is larger and darker than L. delawarensis, with a mantle of 
deep slaty-grey; it is further distinguished by having the zone on the bill ill-defined 
or altogether absent. L. californicus breeds chiefly on the lakes and rivers from the 
Lower Anderson River to Utah, and winters on the Pacific coast of Central America °. 
It also visits the interior, having been noted by Herrera as occasional in the Valley of 
Mexico, and Prof. Ferrari-Perez has recorded a specimen from the State of Vera 
Cruz7. Sumichrast met with the species on the coast of the Gulf of Tehuantepec 
only ? °. 
The Californian Gull breeds in immense numbers on some of the lakes of North 
America, and Mr. Ridgway found an area of several acres on the main island of 
Pyramid Lake thickly crowded with the nests. These were mere heaps of dirt and 
gravel, mingled with rubbish of sticks, bones, and feathers, raised a few inches above 
the surface, and with a slight depression on the top. By far the larger number were 
~ 
BIOL. CENTR.-AMER., Aves, Vol. LII., January 1904. 54 
