6339, ♀, Riverside. Wing, 2.34; tail, 2.14; tarsus, .75; culmen, .52; depth of bill, .14.
48. Vireo pusillus Coues. Least Vireo.—An abundant summer species frequenting willows along streams and, near Tucson, thickets of mesquites. “It is active, restless and very noisy.”
Numerous nests were taken. The only one sent me is a shallower, but nevertheless rather more elaborate structure, than that of V. belli to which, however, it bears a strong resemblance. It is mainly composed of fibrous shreds, apparently obtained from the stalks of some herbaceous plant. The lining is of delicate, bleached grasses, which are very neatly arranged. The eggs are white with a cluster of small black spots about the larger ends. The clutch comprised three, a number which was not exceeded in any of the other nests. The notes relating to this set are as follows: “Tucson, June 11. Nest pensile between the forks of a small mesquite branch, about five feet from the ground, in a 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.
275, ♂ 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.”