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 difierent 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. 334'; 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-1. N. Amer. Birds, 2nd ed. p. 19'; Saunders, Cat. Birds Brit. Mus. xxv. 

 p. 276' ; Gates, 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 extimonim latius extensa : rostro flavo, macula vel fascia subterminali 

 ssepius obsoleta, macula anteapicali intense cocciaea ; pedibus virescentibus ; annulo periopbthalmico 

 miniato ; iride corylina. Long, tota circa 18-.5, aloe 15-2, caudse 5*9, culm. 19, tarsi 2-3. 



5 ad. mari similis, sed minor. Long, tota circa 18-0, alee 15-2. (Descr. maris et feminse ex Ventura, 

 California. Mus. nostr.) 



Ptil. Mem. ptilosi sestivse similis, sed pileo et coUo summo grisescenti-brunneo striolatis : rostro grisescenti- 

 albo, apice flavioanti-albo, nigro subterminaliter vittato ; pedibus sordide virescenti-albis ; iride corylina. 



Ilab. Westekn North Amekica, chiefly in the interior, from Alaska southwards ^, once 

 as far east as Kansas^. — W. Mexico^, Valley of Mexico (Herrera^^), 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 Eiver 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 s, and Prof. Ferrari-Perez has recorded a specimen from the State of Vera 

 Cruz 7. 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. CEKTK.-AMEE.j Aves, Vol. III., January 1904. 54 



