712 BULLETIN 5 0, UNITED STATES NATIONAL MUSEUM 



Hypoiriorchis columbarius (not Falco columharius Linnseus) Stevenson, Prelim, 

 Rep. U. S. Geol. Surv. Terr., 1871, 462 (La Bonte Creek and Green River, 



Wyo.). 

 Aesalon richardsonii Ridgway, Proc. U. S. Nat. M\is., iii, 1880, 192. 

 Aesalon richardsoni Ridgway, Nom. North Amer. Birds, 1881, No. 418. — 



Agersborg, Auk, ii, 1885, 285 (se. South Dakota, migr.).— Gurney, Cat. 

 Birds Prey, 1894, 29. 

 Aesalon Uthofalco richardsoni Goode, U. S. Nat. Mus. Bull. 20, 1883, 305. 



FALCO COLUMBARIUS SUCKLEYI Ridgway 



Black Pigeon Hawk 



Adult male. — Similar to that of Falco columbarius columharius, but 

 very much darker above, dark skate-black to black on the top of head, 

 scapulars, interscapulars, upper wing coverts, and upper back; the 

 lower back, rump, and upper tail coverts lighter, dark slate; the 

 nuchal collar less prominent (the pale areas of the feathers more 

 reduced, more restricted to the hidden basal parts) ; remiges, including 

 the inner secondaries black tipped narrowly with very pale drab gray 

 to whitish, the pale bands or transverse spots on the inner webs 

 smaller, pale ochraceous-buff, and not reaching the edge of the web; 

 rectrices black tipped with white, the three light bands much narrower 

 and reduced to grayish white spots on both webs of the median pair 

 and on the outer webs of all the others, where the longer marks on the 

 inner webs are suffused with pale pinkish buff (in the type specunen 

 these spots entirely wanting) ; the streakmgs on the underparts averag- 

 ing somewhat heavier and darker, fuscous-black to fuscous; entire 

 underparts tmged with pale ochraceous-buff; colors of soft parts as in 

 the nominate race. 



Adult jemale.—^miAQj: to the male, but the upperparts fuscous-black 

 with only a slight slaty tinge on the rump and upper tail coverts, the 

 pale markings on the inner webs of the remiges slightly deeper 

 ochraceous-buff, and similarly reduced in size. 



Juvenal female (no young males seen; sexes probably alike). — Like 

 the adult female but with the crown and occiput dark sepia with black 

 shaft stripes; the feathers of the upper back, upper wing coverts, 

 scapulars and interscapulars narrowly edged with sepia; underparts 

 slightly paler in ground color than adults, pale light ochraceous-buff 

 to light buff. 



Natal down. — Unrecorded. 



Adult male.—SS'mg 186-197 (188.7); tail 115-122 (119.2); culmen 

 from cere 11.5-12.5 (12.1) ; tarsus 35.5-40.5 (38.1) ; middle toe without 

 claw 30-35.5 (36.6 mm.).«« 



«8 Seven specimens from British Columbia, Wasliington, and New Mexico, 



