Col. McCall, in his “Remarks on the habits, &c., of birds met with in Western Texas,” in Proceedings of the Philadelphia Academy, V. p. 222, thus alludes to the Blue Partridge:— “This species I have met with, at different times, throughout a more extended region than either of the former (the Massena Partridge and Gambel’s Partridge), viz.: from Camargo on the lower Rio Grande, to Santa Fé. On the present occasion, they were more numerous between the latter point and Don Ana than elsewhere. They seem to prefer the vicinity of the greater water-courses to interior tracts. They are much more wild than either of the preceding, and being extremely watchful and swift of foot, they elude pursuit with surprising skill, scarcely resorting to flight even in comparatively open, sandy ground. They do not approach the settlements as much as the last. “For the table, all these species, however, possess in a high degree the requisites of plump muscle and delicate flavour. Massena is, perhaps, the best.” The following more extended and beautiful sketch, referring to this Partridge, has been very kindly furnished by the same gentleman (Col. McCall), for our present article:— “The _habitat_ of this species, as I have remarked elsewhere, embraces an extensive region, the limits of which, though not yet positively defined with any degree of accuracy, may, at least with reference to our own territory, be asserted to lie principally within the valley of the Rio Grande or Rio del Norte of Mexico. This valley, although comparatively narrow, contains a country of great extent from north to south; and embraces, in its stretch between the Rocky Mountains and the Gulf of Mexico,—every variety of climate, from the extreme of cold to that of tropical heat. This entire region, not even excepting the narrow mountain-valleys, covered in winter with deep snows, is inhabited by the species under consideration. I have met with it on the Rio Grande and its affluents, from the 25th to the 38th degree of north latitude—that is to say, from below Monterey, in Mexico, along the borders of the San Juan river to its junction with the Rio Grande; and at different points on the latter as high up as the Taos and other northern branches, which gush from the mountain sides. I have also found it, though less frequently, near the head of the Riado creek, which likewise rises in the Rocky Mountains and flows eastwardly to the Canadian; further north than this my examinations did not extend.