Vols XVIT NELSON, Mew North American Birds. 253 
1900 
DESCRIPTIONS OF THIRTY NEW NORTH AMERICAN 
BIRDS, IN THE BIOLOGICAL SURVEY 
COLLECTION: 
BY E. W. NELSON. 
RECENT study of the rich collection of Mexican birds accumu- 
lated by the Biological Survey has thrown much light on the 
southward extension of the life zones found within the United 
States. Many genera are represented in the various faunal areas 
by distinct species, while in other cases wide ranging species are 
broken up into geographic races. The series of specimens from 
almost every part of Mexico now in the collection show the exist- 
ence of various hitherto unsuspected subordinate faunal areas, 
and has proved rich in types of new species and subspecies. The 
present paper gives some of the results of recent preliminary work 
on the collection. 
I am greatly indebted to Mr. Robert Ridgway, Curator, and 
Dr. Chas. W. Richmond, Assistant Curator of Birds, in the U. S. 
National Museum, for cordial assistance during the preparation of 
this paper. All measurements are given in millimeters. 
Crypturus inornatus, sp. nov. BROWN-BACKED TINAMOU. 
Type, No. 158434, @ ad., U. S. Nat. Mus., Biological Survey Collection. 
Metlaltoyuca, Puebla, Mexico, February 14, 1898, E. A. Goldman. 
Distribution. — Dense, humid tropical forests of northern Vera Cruz 
and adjacent part of Puebla. 
Specific characters. — Nearest C. mextcanus, from which the males may 
be distinguished by their deep reddish brown, slightly barred backs and 
more rufous underparts; the females are much deeper, more reddish 
brown both above and below. 
Description of adult male (type). — Crown and forehead black slightly 
suftused with grayish; nape dark reddish brown becoming light vandyke 
brown with a faint purplish bloom on back and sides of neck and fore part 
of shoulders ; shoulders and upper back plain, dark burnt umber; rump and 
upper tail-coverts lighter, more rusty brown and sparsely and indistinctly 
barred with black; primaries and secondaries dark slaty edged with brown- 
ish ; wing-coverts, scapulars and tertials slightly paler brown than back 
and finely and indistinctly maculated but not barred with blackish; sides 
