MYIAECHTIS. 95 



Tigre l.{G.G. Taylor ») ; Nicaeagua, Blewfields ( Wickham 2^), Greyto wn {Holland 1°) , 

 Sucuya^o, Omotepel.^i (Nutting); Costa Rica^ Angostura i^, Sarchi ^^ Grecians, 

 Barranca 28, San Josefs, Pacuar^^ {Carmiol), IxB-zu. {Rogers), Tucuriqui {Arce); 

 Panama, Volcan de Chiriqui, Chitra ^6 and Santa Fe 25 {Arcii). 



We have before us about 130 specimens of this species from various points ranging 

 from Southern Arizona and Northern Mexico down to the State of Panama, and, 

 though we can see obvious differences in selected birds from several places, other speci- 

 mens undoubtedly blend the whole series together. Thus the Arizona birds separated 

 by Mr. Eidgway as M. I. olivascens are, for the most part, as he describes them — pale, 

 with the top of the head hair-brown or olive, very little darker than the back, the tail- 

 feathers in the adult bird without rufous edgings on the inner web. 



Birds from Sonora exactly resemble those from Arizona, while those from Mazatlan 

 are a trifle darker, and have the top of the head more distinctly coloured. Specimens 

 from Northern Yucatan included in the same race by Mr. Ridgway are, again, a trifle 

 darker as regards the head, and we can match them with some specimens from Teapa 

 selected from numbers of the more typical form, and from them, too, Cozumel birds 

 cannot satisfactorily be discriminated. Returning to Mexico we find that birds from 

 the north-eastern States of Nuevo Leon and Tamaulipas and the slopes of the mountains 

 of Northern Vera Cruz are distinguished by their larger size and by the broad rufous 

 edging to the tail-feathers. This latter character seems gradually to disappear in birds 

 from further south ; in those from Orizaba it is but slightly shown, and in Tabasco 

 examples it has altogether disappeared. The Guatemala bird precisely resembles that 

 of Tabasco, nor do we see how that of Costa Rica and the western portion of the State 

 of Panama can be satisfactorily discriminated. Under these circumstances we think it 

 best to unite all these forms under one specific name. The plan adopted by American 

 ornithologists would be much as follows : — We should have M. lawrencii from North- 

 eastern Mexico and a portion of the State of Vera Cruz, M. I. olivascens from Arizona 

 southwards through Western Mexico and Yucatan including Cozumel, and, lastly, 

 M. I. nigricapillus from Vera Cruz southward through Tabasco to Guatemala, Costa 

 Rica, and the State of Panama ; but such an arrangement would not enable us to 

 name with certainty many intermediate birds ; we therefore prefer to include them all 

 under one comprehensive name. 



Myiarchm lawrencii is a common bird wherever it is found, its chief abode being the 

 low lands bordering both oceans up to an elevation of 4000 or 5000 feet. On theTres 

 Marias Islands Grayson says it is aburidant in all parts of the woods. In Guatemala it 

 is common, and though more often seen in the forests of the hotter parts of the country 

 may not unfrequently be met with in the temperate districts, such as Coban, Tactic, 

 and Duenas. 



The eggs of this species taken by M. Boucard at Talea ^ are described as pure white. 



