Vol. XLV 
1897 Nerson, Mew Birds from Mexico and Guatemala. 55 
857 + _ : : 
Description.—Vhe males of this bird are distinguishable from chrysolema 
of the southern table-lands of Mexico by the greater extension of the 
vinaceous coloration on both upper and lower surfaces of the body. It is 
a lighter and brighter shade of this color than on chrysolema and extends 
over the crown, nape, sides of neck, shoulders, rump, lesser and middle 
wing-coverts and sides of chest and flanks. In addition, the greater wing- 
coverts are more or less broadly bordered with the same. The exposed 
portion of the feathers of the folded wings as well as the back has the pale 
brown ground color suffused with a wash of this color, thus shading the 
entire upper surface behind the black area on the head. This general 
suffusion of vinaceous affords the readiest means of distinguishing this 
bird from chrysolema. The yellow on the throat is paler in oaxace than 
in chrysolema. The females differ from those of chrysolema by being 
lighter brown above with a greater suffusion of pale vinaceous on the 
dorsal surface and along the flanks. The Oaxacan form averages a little 
smaller than chrysolema. , 
Unfortunately my series of sixteen adult Oaxacan birds are all 
in summer plumage and more or less worn. A comparison of well 
plumaged birds with the fine series of chryso/ema would, no doubt, 
emphasize the differences noted. Ofocoris peregrina of Bogota is 
very similar in coloration to chrysolema of the table-lands of central 
Mexico. Judging from the two specimens from Bogota in the 
U.S. National Museum collection, it is a smaller form than either 
oaxace or chrysolema. While on the highlands of Chiapas and 
Guatemala I looked carefully for Horned Larks but did not see a 
single individual. 
O. alpestris oaxace was found breeding rather commonly in the 
Valley of Oaxaca and also along the salt flats near the sea about 
San Mateo del Mar. So far as known, its range is limited to parts 
of the State of Oaxaca. To the north its range meets that of 
chrysolema. So far as our collections show, none of the several 
forms of QO¢ocoris found in winter along the northern border of 
Mexico range south to the southern highlands about the Valley of 
Mexico and Plains of Puebla where true chryso/ema abounds. 
Calocitta formosa azurea, new subspecies. BLUE-BACKED 
CALOCITTA. 
Type, No. 144529, U.S. Nat. Museum, Dept. Agric. coll., ¢, Huehuetan, 
Chiapas, Mexico, February 24, 1896. Collected by E. W. Nelson and E. 
A. Goldman (Orig. No. 3559). 
Distribution— The Pacific coast of Chiapas and thence southeasterly 
through Guatemala and other parts of Central America. 
