252 HISTORY OF THE 



7th, 1.70x1.38, 1.68x1.43; in color white, or rather bluish white, 

 without markings or shell stains; in form, roundish. 



GENUS CIRCUS LACEPEDE. 



"Form very slender, the wings and tail very long, the head small, bill weak, 

 and feet slender. Face surrounded by a ruff of stiff, compact feathers, as in the 

 Owls (nearly obsolete in some species). Bill weak, much compressed; the upper 

 outline of the cere greatly ascending basally, and arched posteriorly, the com- 

 missure with a faint lobe; nostril oval, horizontal. Loral bristles fine and 

 elongated, curving upwards, their ends reaching above the top of the cere. Su- 

 perciliary shield small, but prominent. Tarsus more than twice the middle toe, 

 slender, and with perfect frontal and posterior continuous series of regular trans- 

 verse scutellse; toes slender, the outer longer than the inner, claws strongly 

 curved, very acute. Wings very long, the third or fourth quills longest; first 

 shorter than the sixth; outer three to five with inner webs sinuated. Tail very 

 long, about two-thirds the wing, rounded." 



Circus hudsonius (LINN.). 



MARSH HAWK. 

 PLATE XV. 



Resident; abundant. Begin laying about the first of May. 



B. 38. K. 430. C. 489. G. 199, 115. U. 331. 



HABITAT. The whole of North America; south in winter to 

 Panama, Bahamas and Cuba. 



SP. CHAR. Adult male: Head, neck, chest and upper parts uniform light 

 bluish gray, the occiput darker and streaked with whitish, tinged with rusty; 

 longer quills blackish toward the tips; upper tail coverts plain white; tail bluish 

 gray, mottled with white toward base, narrowly tipped with white, crossed near 

 end by a broad blackish band, and, anterior to this, by five to seven narrower 

 and less distinct dusky bands; the inner webs whitish, with the bands more 

 distinct, and sometimes tinged with rusty; under surface of wing (except termi- 

 nal third or more of quills), and lower parts from breast backward, white, the 

 larger under wing coverts and lower parts with more or less numerous trans- 

 verse (usually cordate) spots of rusty or brown. Adult female: Above, dusky 

 brown, the head and neck streaked, the lesser wing coverts spotted, and feath- 

 ers of rump edged, with rusty; upper tail coverts plain white; tail brown, paler 

 at tip, and crossed by six or seven very regular and distinct bands of blackish; 

 the brownish spaces becoming gradually paler and more rusty to outer feathers, 

 which are more ochraceous; sides of head light dull buffy, with a dusky stripe 

 behind eye; feathers of 'facial disk' buff, each with a median streak of brown; 

 chin, throat, and lower parts generally, dull buffy whitish, varying to deeper 

 dull buffy, striped (except on chin and throat) with brown, the stripes becoming 

 gradually much narrower posteriorly. Young: Above, blackish brown, the 

 head and neck streaked and lesser wing coverts spotted with deep rusty; upper 

 tail coverts white, tinged more or less with ochraceous; tail crossed by four 

 broad bands of black, the interspaces being dark brown on middle feathers, 



