74 U. S. P. R. R. EXP. AND SURVEYS—ZOOLOGY—GENERAL REPORT. 
This species, in addition to the names cited above, is also sometimes called Correo camino. 
It is common in Texas and California, and always excites attention by its large size and peculiar 
habits. In a very large series of this species I find great variations in size, although but little 
in color. As a general rule, however, skins from California are considerably larger than those 
from Northern Mexico and Texas. 
The difference between this species and G. afinis of Hartlaub are very appreciable. The latter 
is decidedly smaller ; the bill is much smaller, shorter, and both culmen and commissure are 
curved almost from the base of the bill, instead of straight nearly to the tip. The culmen is 
shorter than the head instead of longer, and the nostril is opposite the middle of the commissure 
instead of decidedly posterior to the same point. The tarsi are only about two inches long; the 
culmen 1.30 inches. The tertials and outer surface of the wings are glossed with coppery violet 
instead of green; the lateral tail feathers with green instead of blue. The under parts are 
nearly uniform brownish yellow or whitish, the sides of the breast alone with a few sharply 
defined, longitudinal streaks of black, instead of brownish cinnamon; breast feathers edged 
with hoary white, and much streaked centrally, though narrowly, with black ; the belly dirty 
white. The length is about 18 inches; the wing 5.50; the tail 9.75. 
If Hartlaub’s quotation of 1829, as the date of the Saurothera californiana, Lesson, be correct, 
this name will take precedence among the more modern ones. Should this not be the case, then 
the next in order will probably be that of Wagler. Iam unable to say what the relationships 
of G. velox of Karwinski, (Miinchner Gelehrte Anzeigen, III, 1836, 95,) may be, not having 
this volume at hand for reference. 
The Phasianus mexicanus of Gmelin, I, 1788, 741, based on the Hoitlallotl of Hernandez, 
(Nova Anim. 1690, app. 25,) in all probability refers to a species of Geococcyx, but it is entirely 
impossible to say which. Hernandez was most likely to have met with the southern species, or 
afinis. Still, in the entire impossibility of ever coming to a decision, either in reference to 
Phasianus mexicanus, or Upupa mexicana of Gmelin, it seems much better to drop the consid- 
eration of these names and to confine investigations to more modern authors. 
