36 PROCEEDINGS OF THE NATIONAL MUSEUM VOL. 05 
seum of Natural History. In all, 84 skins have been examined, 
these being from localities well distributed throughout the range of 
the species. 
Male and female in Herpetotheres cachinnans are alike in size and 
in color and marking, and individual variation, both in measurement 
and in coloration, is greater than has been supposed. Birds in the 
first year have the feathers of the dorsum and wing coverts margined 
with light, bright brown, but otherwise appear like adults. The 
number of light cross bars on the tail varies from four to five, with 
considerable variation in width; in some individuals the bars become 
divided into oval spots. The amount of dark streaking on the crown 
is highly variable, as is the extent of spotting on the under wing 
coverts. In some birds there is a deep buffy tinge in the ordinarily 
white markings of head and under surface, a variation which may 
appear anywhere in the range of the species, being intensified in 
regions of heavy rainfall. There is no question that during the rainy 
season this color may be produced or intensified by stain acquired 
from wet vegetation and from the ground during feeding. Conversely, 
birds from drier areas, or those taken during the dry season, are 
cleaner and therefore whiter. 
Tail measurements are uncertain because of excessive wear. This 
is particularly the case where the birds have been feeding over burned 
areas, a common habit; apparently they often come down to places 
where the ashes are still so hot as actually to char the ends of the tail 
feathers. 
With these facts understood the series examined may be separated 
into three geographic races, as outlined in the following paragraphs: 
Herpetotheres cachinnans chapmani Bangs and Penard: 
Herpetotheres cachinnans chapmani Banes and PENARD, Bull. Mus. Comp. Zodl., 
vol. 62, 1918, p. 37 (Santa Lucia, Rio Hondo, Quintana Roo, México). 
Generally similar to H. c. cachinnans but averaging more grayish 
brown above; the light margins on the dorsal feathering of the im- 
mature dress brighter, lighter brown, being brighter in color than in 
queribundus. 
Range: The tropical areas of México and Guatemala, probably also 
British Honduras, possibly into northern Honduras and El Salvador. 
Birds from northwestern México, judged from the relatively few 
specimens that have come from that area, have been supposed to 
average a little larger than from elsewhere in the north, but are equaled 
by individual birds from many other localities, so much that the race 
excubitor, described recently by van Rossem? cannot be separated. 
2 Herpetotheres cachinnans eacubitor van Rossem, Trans. San Diego Soc. Nat. Hist., vol. 9, Nov. 21, 1938, 
p. 10 (Volean de Colima, southern Jalisco). 
