546 PROCEEDINGS OF THE XATIOXAL ilUSEUM. vol.43. 



Measwcments. — Total length (in flesh), 1100-11 70 mm.; extent 

 of whig, 1755-1845. 



Male:^ Wing, 445-493 (average, 471.7) mm.; tail, 162-192 (179.9); 

 exposed ciilmen, 132-157 (144.3); height of bill at base, 26-31 (28); 

 tarsus, 165-193 (181.6); middle toe, 99-112.5 (105.9). 



Female: 2 Wing, 440-475 (455.5); tail, 164-182 (174.2); exposed 

 culmen, 120.5-150 (137.2); height of bill at base, 25-28 (26.1); tarsus, 

 157-183 (170.5); middle toe, 89-107.5 (100.7). 



Type locality. — Egg Island, Great Salt Lake, Utah. 



Geographical distribution. — Western United States to southwestern 

 ]\Iexico: In summer chiefly the Lower Austral, Upper Austral, and 

 Transition zones, north to Douglas County, southern Wyoming; 

 Grace, southern Idaho; probably also to Montana and eastern Wash- 

 ington; west to central Washington (probably); central Oregon 

 (probably); Nevada; Colorado River near Riverside Mountain, and 

 Pelican Island, Sal ton Sea, southeastern California; and the Pacific 

 Ocean at the United States and Mexican boundary line;^ south to 

 Gardner's Laguna, Sal ton River, northern Lower California; Guay- 

 mas, central western Sonora;* Santa Cruz River west of the Pata- 

 gonia Mountains, Arizona; Fort Fillmore and Carlsbad, southern 

 New Mexico; Tornillo Creek, near Boquillas, central western Texas; 

 and probably also northern Chihuahua; east to Kerr County, central 

 Texas (probably); Denver, central Colorado; Douglas County, east- 

 ern Wyoming; and probably eastern Montana. Winters from Texas 

 and Arizona south to Manzanillo, Colima, Mexico. In migration 

 wanders west to the Sacramento Valley, California, and east to 

 Corpus Christi, Texas. 



This western race is apparently just like Ardea herodias ivardi in 

 color, but is decidedly smaller throughout. It differs from Ardea 

 herodias adoxa, of the West Indies, in somewhat paler upper parts 

 and sHghtly larger size. It is, in fact, closer m characters to tliis 

 than to either Ardea herodias herodias or Ardea herodias wardi. The 

 Juvenal plumage of Ardea herodias treganzai is distinguishable from 

 that of Ardea herodias herodias by its decidedly paler upper parts 

 and usually paler neck. 



There seems to be no difference of consequence between birds 

 from various parts of this bird's range, as above defined. An imma- 

 ture specimen from Bro^Misville, Texas (No. 30259, J. Dwight), is 

 apparently this form; as is also a bird from Corpus Clmsti (No. 

 79707, Amer. Mus. Nat. Hist.), taken at the late date of April 11 

 (1889). We have only the head and part of the neck of an immature, 



1 Fourteen specimens, from Arizona, New Mexico, Texas, Idaho, and California, including seven not 

 examined by the writer, but measured by Mr. Joseph Grinnell. 



2 Twenty-two specimens, from Arizona, Texas, Utah, Wyoming, Montana, Lower California, and Chi- 

 huahua, including seven not examined by the writer, but measured by Mr. Joseph Grinnell. 



2 Probably not breeding here. 



* Probably Ardea herodias treganzai; eggs in the United States National Museum. 



