BIRDS OF NORTH AND MIDDLE AMERICA. 655 



specimens that I have seen which seem without doubt referable to this 

 form are from certain islands of the Bahama group. 



(2) Oeothhypis tricJms ignota. — This is the southern -coast form, whose 

 breeding range extends from the Dismal Swamp, in southeastern Vir- 

 ginia, to Cape Florida, and westward along the Gulf coast at least to 

 Louisiana, probably to eastern Texas. This is much the darkest of all, 

 has the wing more rounded, and is the only one in which the length of 

 the tail is nearly (sometimes quite) equal to that of the wing. 



(3) OeoMypis trichas hrachidactyla. — The northern and trans- 

 Alleghenian form, somewhat intermediate in coloration between G. t. 

 trichas and G. t. ignota, but clearly distinct from either. With about 

 the same size as Q. t. ignota, but with the tail relatively much shorter, 

 it is otherwise more like O. t. trichas, but has the under parts mostly 

 yellow and the upper parts a more decided olive-green. The alleged 

 difference in the wing-formula between this subspecies' and G. t. 

 trichasl have not been able to verify. This form is first met with as 

 a probable or possible summer resident in northern New Jersey and 

 on Long Island, whence it extends northward, to the exclusion of G. 

 t. trichas, and from the New England States and maritime British 

 Provinces westward to eastern North Dakota, and thence southward 

 throughout the Mississippi Valley, east of the Great Plains, breeding 

 over the whole of this extensive area, and migrating southward through 

 eastern Mexico and Central America as far as Costa Rica, as well as 

 through the exclusive summer habitat of G. t. trichas, along the Atlan- 

 tic seaboard, to certain of the West Indies and other islands of the 

 Caribbean Sea. 



(4) Geothh/pis trichas occidentalis. — The arid region form, which 

 agrees in size, brighter olives-green of upper parts, and greater exten- 

 sion of yellow on the under surface with G. t. hrachidactyla, but differs 

 from that, as well as from the other two eastern forms, in having the 

 post-facial band white instead of light gray, and the yellow of the under 

 parts of a warmer or more orange hue. The range of this well-marked 

 subspecies begins at the western limit of that of G. t. hrachidactyla 

 (somewhere about the middle of the Great Plains) and extends west- 

 ward to the Pacific coast in southern California and northern Lower 

 California, and from the northern boundary of the United States to 

 northern Mexico. I am unable to trace it farther southward in winter 

 than Cape St. Lucas and the State of Sinaloa in western Mexico. 



(5) Geothlypis trichas arisela. — The Pacific coast form, replacing 

 G. t. occidentalis from Los Angeles County, California, to British 

 Columbia. - Very similar to G. t. occidentalis in coloration, but with 

 the bill much smaller (exposed culmen very rarely 11 mm. , the mini- 

 mum length in G. t. occidentalis), the whitish post-facial band averag- 

 ing narrower, and the general coloration less intensified. This form 



'See William Palmer, Auk, xvii, 1900, 226, 227. 



