30. TREE SWALLOW. 6-1/4 in. (Iridoprocne bicolor. 614.)
Metallic blue-green; _shining white below_; tail appears nearly square at end in flight; often seen skimming near the surface of still water. *Barn Swallow. *Purple Martin.
31. CARDINAL. 8-1/2 in. (Cardinalis cardinalis. 593.)
Bright red, including large blunt bill; _crested_; black markings on face and throat; female olive-gray, tinged lightly with red and obscurely marked; fine songster. *Tanagers.
32. WHITE-THROATED SPARROW. 7 in. (Zonotrichia albicollis. 558.)
_White throat_; unmarked ashy breast; whitish on belly; crown striped with black and white; broad white stripe over the eye shading to yellow in front; in flocks about shrubbery; clear, sweet whistle, "pee-bod-dee-dee-dee." *White-crowned Sparrow.
33. MARSH HAWK. 22 in. (Circus hudsonius. 331.)
Bluish gray, showing light streaks; gray below, belly white marked with brown; tail barred; _white rump patch_; female brown, barred and streaked more heavily; note shrill.
34. CHIPPING SPARROW. 5-3/4 in. (Spizella socialis. 560.)
Streaked; _plain ashy breast_; two faint white wing-bars; _chestnut-brown cap_; whitish line over eye; song, a strong clear trill. *Field Sparrow. *Tree Sparrow.
35. MOURNING DOVE. 12 in. (Zenaidura macroura. 316.)
Gray-blue, tinged with brownish; tail broadly tipped with white, _tapering to a narrow point_; sides of neck iridescent; marked with black on wings and sides of head; rapid whistling flight; note, "coo-oo." *Pigeon. *Cuckoos.
36. WINTER WREN. 4-1/4 in. (Olbiorchiles hiemalis. 722.)
Dark tawny-brown, barred on wings and tail; lighter below, barred posteriorly; pale line over eye; _stub tail, carried erect_; very fine song. *Other Wrens.
37. VESPER SPARROW. 6-1/4 in. (Poæcetes gramineus. 540.)
Streaked above and below; underparts whitish, tinged with buff across breast and on sides; shows _two conspicuous white tail feathers in flight_; noteworthy song. *Female Purple Finch.
38. MYRTLE WARBLER. 5-1/2 in. (Dendroica coronata. 655.)
Blue-gray, streaked; crown, _rump_ and spot on each side of breast, _yellow_; white below, marked on breast and sides with black; usually in small flocks. *Magnolia Warbler.
39. SWAMP SPARROW. 5-3/4 in. (Melospiza georgiana. 584.)