Résumé.

I.—It can now be said categorically that the Crow occurs in Colorado in the guise of two subspecies, viz., brachyrhynchos and hesperis, both being found on the eastern slope, and only the latter on the western slope of the Rocky Mountains.

II.—The above conclusion stands if my determinations of the skins I have studied be correct; if my determinations be incorrect they show that the criteria by which these two subspecies are differentiated, are too subtile and refined for an ordinary ornithologist like myself to grasp and apply, or that the described differences between these two subspecies break down with the Crows found in Weld County.

**Measurements of *hesperis* skins (8: millimeters).**
				Bill
				┌─────┴─────┐
				│	│
Locality	Sex	Wing	Tail	Length	Depth	Tarsus
Weld Co.	♂	303	172	49	18	57
" "	♂	312	178	45	17	56
Ignacio	♂	317	183	44	17	53