Brewster on a Collection of Arizona Birds. 1 45 
thicket of weeds and brush. Incubation commenced. Female 
shot. This species seems to abandon a nest if it is found before 
any eggs are laid.” 
205, $ ad., Cienega Station, April 15. Length, 5; extent, 7.10; wing, 
2.21: tail, 2.25. “Iris dark brown; bill dark above, light below; legs 
dark.” 
235, $ ad., Tucson, April 19. Length, 5.10; extent, 7.30; wing, 2.23; 
tail, 2.25. 
262, $ ad., Tucson, April 22; Length, 6; extent, 7.10; wing, 2.28; 
tail, 2.34. 
27 5, $ ad., Tucson, April 25. Length, 5; extent, 7; wing, 2.21; 
tail, 2.25. 
276, $ ad., same locality and date. Length, 4.90; extent, 6.90; wing, 
2.18; tail, 2.25. 
282, $ ad., same locality and date. Length, 5; extent. 7.10; wing, 
2.30; tail, 2.30. 
461, $ ad.. Camp Lowell. May 31. Length, 5; extent, 6.90; wing, 
2.21; tail, 2.25. “Laying.” N 
499, $ ad., Tucson, June 7. Lengthy; extent, 6.90. Skin lost. 
589, $ ad.. Camp Lowell, June 24. Length, 4.80; extent, 6.80; wing, 
2.21 ; tail, 2.25. 
49. Vireo vicinior Cones. Gray Vireo. — The only indi- 
viduals met with were a male and female — apparently a mated 
pair — which were taken at Tucson, on April 26. “They were 
in low brush and were very shy.” 
286, $ ad., Tucson, April 26. Length, 5.60; extent, 8.20; wing, 2.63; 
tail, 2.67; tarsus, .80. 
287, $ ad., same locality and date. Length, 5.60; extent, 8.30; wing, 
2.58; tail, 2.70; tarsus, .80. “Iris dark brown; bill plumbeous, darkest 
above; legs light plumbeous.” 
50. Lanius ludovicianus excubitorides ( Sw .) Cones. 
White-rljmped Shrike. — - “Common and generally distribu- 
ted.” 
It is unfortunate that so much prominence has been given to the white 
rump of excubitorides as a distinguishing character, for I have yet to see a 
good series of Shrikes from any Western locality, excepting, possibly, Ar- 
izona, which did not afford a considerable percentage of dark-rumped 
birds; and convers-ely, it is bv no means difficult to find light-rumped 
specimens in the East. The same instability also affects most of the other 
characters which have been assigned to excubitorides. as is sufficiently 
shown by the various conflicting rulings of the authorities regarding the 
precise definition and limits of distribution of this troublesome race. The 
only differential points which seem to me to hold good with any number 
of specimens, are the lighter, purer ash of the upper parts as compared 
with those of ludovicianus . and the smaller and very much weaker bill. 
