656 BULLETIN 50. UNITED STATES NATIONAL MUSEUM. 



extends in winter to Cape St. Lucas, but is mainly resident, at least 

 in the more southern parts of its range. 



(6) Geothlyph tri^has sinuosa. — A small form (slightly smaller even 

 than G. t. trichas), apparently confined to the salt marshes about San 

 Francisco Bay. The coloration is essentially identical with that of 

 G. t. arizela, but slightly darker, especially on the upper parts and 

 flanks. 



(7) Geothlypis trichas modesta.— The resident form of western Mex- 

 ico (States of Sinaloa, Jalisco, and Colima and Territory of Tepic'). 

 This form is practically identical with G. t. a/rizda in coloration and 

 general dimensions, but has the bill much larger (about the same size 

 as in G. t. occidentaKs), and would hardly be recognized by name were 

 it not for the fact that it has a definite range far removed from that 

 of G. t. arisela, the much more brightly colored G. t. occidentalis com- 

 ing between the two. 



(8) Geothlypis trichas melanops. — This is the subspecies of eastern 

 Mexico, and is evidently an oilshoot from G. t. occidentalis, from which 

 it differs in larger size, in having the under parts entirely rich yellow, 

 and the white post-facial band broader and somewhat tinged with yel- 

 low on its lateral branches. Some specimens from Chihuahua, north 

 ern Mexico, are clearly intermediate between this very strongly marked 

 subspecies and G. t. occidentalis. 



Geothlypis heldingi, of the Cape St. Lucas district, and the several 

 forms peculiar to the Bahama Islands are evidently derived from the 

 same "original stock" as the forms of G. trichas, but being no longer 

 connected by intermediates may be considered specifically distinct. 

 All these are much larger than any of the G. trichas group. G. hddingi 

 has the post-facial band entirely yellow, a character shared by a much 

 smaller species of eastern Mexico {G. flavovelatd), two of the Bahama 

 forms ( G. coryi and G. flamida) having this marking also yellow except 

 across the crown, being thus intermediate so far as this character is 

 concerned, the other Bahama forma having the post- facial band gray 

 or grayish white, as in the G. trichas group. 



The Bahaman insular forms present a puzzling problem, which can 

 not be solved until many more specimens have been secured, especially 

 from the islands of Great Bahama," Abaco, Andros, and Eleuthera. 

 Three easily recognizable forms unquestionably inhabit the small 

 island of New Providence, while two are certainly inhabitants of 

 Abaco; therefore they can not be subspecies of one form. One of 

 the three New Providence forms ( G. rostrata) is very different from 

 any inhabiting the other islands; the other two' resemble, respectively, 



'A specimen (female) from Tehuacan, Pueblo, is doubtfully referred to the same 

 form; also one from Ortiz, Sonora. 



* I have not been able to examine a specimen from the island of Great Bahama. 



' These second and third New Providence forms are O.flavida, representing G. coryi, 

 and O. maynardi, representing G. tamieri. 



