DISTRIBUTION OF THE BIRDS OF VERA CRUZ. 555 



trunk of the tree around which it is creeping. By means of its elongated and strong beak, 

 it readily procures its means of subsistence among the crevices of the bark. I have found 

 in the stomach of one of these birds a tree-frog, Hyla myotympanum, which it had probably 

 captured among the tufts of the uEchmoeas epiphytes, where these reptiles resort during the 

 dry season and even undergo their metamorphoses. 



The beak of the II. emigrans presents notable differences, according to the sex or age(?) 

 of the individual. In the young bird it is short and but slightly bent. I know not for 

 what reasons the specific name of emigrant has been given to this bird. I feel very sure 

 that those that are found among the mountains of Orizaba are resident there. It would 

 not however be surprising if this species were to be found inhabiting the hot country. 



Such a distribution may be cited in regard to : — 



131. Picolaptes affinis. Hot, temperate, and alpine regions. This bird inhabits the three 

 regions, and in the alpine ascends to the height of at least 2500 metres. Like the Melon- 

 erpes formcivorus it is especially fond of the oak woods. In the State of Vera Cruz these 

 trees, of different species, seem to characterize it is true, two zones of different tempera- 

 ture and altitude ; one situated on the upper confines of the hot lands, the other in the 

 alpine region. It is not surprising that a species (as is the case with this Melanerpes, and 

 perhaps with the P. affinis) that is resident by choice in the forests of oaks, should appear 

 wherever the abundance of these trees offers the same favorable conditions for their ex- 

 istence. 



132. Glyphorynchus major. Hot region. Exclusively confined within the limits of the hot 

 region. 



133. Siltasomus syhioides. Hot region. Also confined to the forests of the hot country, 

 which it very rarely leaves. It is cpaite common among the oak woods at Potrero — 590 

 metres. 



134. Xenops mexicanus. Hot region. Belonging to the same localities with the pre- 

 ceding. 



135. Synallaxis erythrothorax. Hot region. Peculiar to the hot region, which it never 

 leaves. 



136. Anabates rubiginosvs. Hot region. 



137. Anabaztenops variegaticeps. Hot region. 



138. Automolus cerinnigidaris. Hot region. 



139. Sclerunis mexicanus. Hot region. The last four, while they all have their general 

 centre of propagation in the hot region, are also occasionally seen in localities having a 

 greater altitude. This is especially true of Nos. 136, 137, and 139, which are thus found 

 to the foot of the alpine region, at Orizaba, at the height of 1300 metres. 



FoRMICARIID^. 



The species belonging to this family found in Mexico as well as in the rest of tropical 

 America, are, for the most part, residents of the moist forests, the soil of which, covered 

 with a thick coating of vegetable mould, mingled with organic debris of all kinds, offers 

 an abundant harvest of insects and larvae. The eastern portions of the department 

 of Vera Cruz, spoken of in these notes as the hot region, presents, to the few Formi- 

 cariidce, that inhabit it, all the favorable conditions that their organization requires, and there 

 we must chiefly look for them. But the presence of one species of this family in the alpine 



