252 BULLETIN 19 7, UNITED STATES NATIONAL MUSEUM 



haps rarely five. They seem to be indistinguishable from those of 

 Hutton's vireo. Those that I have seen are sparingly marked with 

 very dark brown or blackish, but others have mentioned markings in 

 lighter shades of brown. The measurements of 25 eggs average 18.1 

 by 13.6 millimeters ; the eggs showing the four extremes measure 19.5 

 by 13.6, 17.5 by 14.5, 16.9 by 13.6, and 18.2 by 13.2 millimeters. 



Plumages. — The molts and plumages are apparently in the same 

 sequence as those of the species elsewhere. Van Tyne and Sutton 

 (1937) say that a male in juvenal plumage, collected on July 18, 

 "is paler and browner above than the adult, with broad edgings of 

 bright yellowish green on the outer webs of the flight feathers. The 

 throat is much like that of the adult, but the belly is whiter in the 

 center and more buffy on the sides." Mr. Swarth (1904) says: 



Specimens taken the middle of Augnst are in the midst of the moult, but some 

 secured the first week in September have nearly completed the change. Birds 

 taken at this time are generally rather darker and more olivaceous than spring 

 specimens, vpith more greenish-yellow on the edges of the wing and tail feathers. 

 Aside from these seasonal differences the series of specimens I secured here shows 

 very little variation in color, and I took none which approach huttoni very closely ; 

 but I have a male specimen of huttoni taken at Los Angeles on December 6th, 

 1898, which is almost indistinguishable from autumnal examples of stcpheiiM; 

 being quite as pale in coloration, but having rather more greenish-yellow streak- 

 ings on the sides and flanks than is the case with that race. The bill is also of 

 the larger size which distinguishes the coast race. 



VIREO HUTTONI COGNATUS Kidgway 



FRAZAR'S VIREO 



HABITS 



This is another pale race that is resident in the Cape San Lucas 

 district of Lower California. Mr. Ridgway (1904) describes it as 

 "similar to V. h. stephensi, but wing averaging decidedly shorter, tar- 

 sus longer, and coloration paler. Adults with olive-gray of upper 

 parts slightly paler and greenish olive of rump and upper tail-coverts 

 much less pronounced, under parts whiter, the chest, etc; much less 

 strongly tinged with olive-buff. Young with under tail-coverts, anal 

 region and lower abdomen much less strongly tinged with buff." 



William Brewster (1902) remarks that "Lower California speci- 

 mens of Stephens's Vireo have larger bills than those from Arizona, 

 but I can discover no other differences." His specimens were col- 

 lected by M. Abbott Frazar, for whom the subspecies was named. He 

 says of its haunts : 



Mr. Belding, who was the first to detect Stephens's Vireo in Lower California, 

 gives it in his list of mountain birds as "common above 3,000 feet altitude," but 

 "not observed below this." Mr. Frazar found it numerous among the pines on 

 the Sierra de la Laguna in May and early June, but none of the specimens killed 

 there showed any signs of breeding. He also met with it at San Jos6 del Rancho 



