202 Brewster on a Collection of Arizona Birds . 
dead twigs protecting its exterior and a scanty lining of fine 
grasses. The female was sitting on four eggs, which were on 
the point of hatching. The only specimen saved measures 1.13 
X-82. It is pale greenish-blue, absolutely without markings, 
and closely resembles a Robin’s egg. “The others were similar, 
as were three eggs of a set taken in 1876, and two of one found 
in 1880.” 
Of the fifteen specimens collected only four have the bill wholly black. 
With all the others there is more or less flesh-color, which, although usually 
confined to the base and tip of the lower mandible, sometimes spreads 
over nearly the whole of the bill below as well as encroaching on the 
maxilla at the tomia, and occasionally even occupies a narrow central 
space along the ridge of the culmen above the nostrils. Mr. Henshaw has 
remarked on this feature, which he considers peculiar to young birds. If 
this view be correct it must require several years for the bill to become 
unicolor. 
98. Eremophila alpestris chrysolaema ( Wagli) Coues. 
Mexican Shore Lark. — The only Shore Lark in the collec- 
tion, a young bird in first plumage, taken on the plains at the 
base of the Santa Rita Mountains, has been referred by Mr. 
Ridgwav to the above race. 
99. Tyrannus verticalis Say. Arkansas Flycatcher. 
— Although this species was much less numerous than the follow- 
ing, especially after the spring migrants had gone, a few pairs 
were found breeding about Camp Lowell, where a nest containing 
three slightly incubated eggs was taken on June 20. The col- 
lection includes skins from Tucson and Camp Lowell. 
100. Tyrannus vociferans Swains. Cassin’s Flycatcher. 
— * "Abundant in summer. Neither verticalis nor vociferans 
winters in Arizona.” Specimens were collected at Tombstone, 
Tucson, and among the Santa Rita Mountains. 
The peculiar attenuation of the primaries in this species has been freely 
commented on by authors, but no one seems to have noticed that this 
character, at least as applied in diagnoses, is to be found in only the male 
of T . vociferans. Nevertheless this is true of the somewhat large series 
of specimens before me, among which there is a decided and very constant 
sexual difference in the shape of the outer four primary feathers. All the 
adult males have them abruptly and deeply notched on the inner webs about 
half an inch from the tip, the emargination extending more than half-way to 
the shaft and reducing the width of the feather, terminally, to about .12 of 
an inch. In the females these feathers show no well-defined notching, the 
tips being simply tapered, usually with a slightly concave outline, although 
the outline is sometimes actually rounded. A young male from Riverside, 
