NO. 1910. REVISION OF BUT0RIDE8 VIRE8CEN8—0BERH0L8ER. 535 



Geographical distribution. — Southeastern North America, most of 

 Mexico, and northern Central America: north to Prospect, central 

 Nova Scotia; St. John, southern New Brunswick; Calais and Pitts- 

 field, southern Maine; Montreal, southern Quebec; Ottawa, Guelph, 

 and Neebish Island, southern Ontario; Grand Rapids, southern Mich- 

 igan; Sturgeon Bay and Kelley Brook, northern Wisconsin; Minne- 

 apolis, central Minnesota; and Fort Sisseton, northeastern South 

 Dakota; west to Fort Sisseton, eastern South Dakota; Nehgh and 

 Gibbon, eastern Nebraska; western Kansas; Fort Reno and Chat- 

 tanooga, central Oklahoma; Pecos City and Fort Stockton, western 

 Texas; casually to Loveland, central Colorado, and Rinconada, 

 northern New Mexico;^ Tampico, eastern Tamaulipas; Isla de los 

 Frijoles, and Rivera, eastern Vera Cruz; San Mateo, near City of 

 Mexico, Mexico; and western Mexico (from Patzcuaro, western 

 Michoacan, and Ocotlah, eastern Jahsco) to the Pacific coast north 

 as far as Mazatlan, southern Sinaloa; south to the Dry Tortugas, 

 Florida; the Gulf coast of the United States, from Florida to Browns- 

 ville, Texas; the Pacific coast of southern Mexico, at Manzanillo 

 (CoUma), Papayo, (Guerrero), and Tonala, (Cliiapas) ; Chiapam 

 (=Champerico) and Duenas, southern Guatemala; Omoa and Ceiba, 

 northern Honduras; east to Ceiba, Honduras, and the eastern coasts 

 of British Honduras, Yucatan, Mexico, the United States, and Nova 

 Scotia. Winters chiefly in Honduras, Guatemala, central and 

 southern Mexico, Florida, and the Bermuda Islands. Accidental at 

 Fajardo, Porto Rico, 



Throughout the wide range of this form there is surprisingly lit- 

 tle geographical variation, and no further subspecific subdivision 

 seems advisable, at least with present material. Birds from the 

 northeastern United States represent the extreme differentiation of 

 Butorides virescens mrescens, with which those from South Carolina, 

 the tj^e-locality, seem to be in all respects practically identical. 

 Breeding birds from the mainland of Florida, from southern Ala- 

 bama, southern ^Mississippi, and southern Texas are absolutely indis- 

 tinguishable in color from examples taken in New York and Penn- 

 sylvania; but in size they average very shghtly smaller. Specimens 

 of a considerable series from the islands of the Dry Tortugas, Florida, 

 off the southern end of the Florida peninsula, are scarcely smaller than 

 those from the Florida mainland, but are mostly less bluish or glaucous 

 green above; which difference, however, seems not to be of geographi- 

 cal significance, since it occurs more or less as an individual variation 

 throughout the entire range of the species. 



From southern Tamaulipas to Tabasco, along the eastern coast of 

 Mexico, occur some birds which are darker than those of usual colors 

 from the eastern United States; and which are, in the males, about 



> M. Surber, spring (April to June), 1904, one seen. 



