242 Messrs. Salvin and Godman on Mexican Birds. 



northern distribution may be almost said to define the 

 boundary between the Nearctic and Neotropical Regions. On 

 the western side of Mexico the Psittacidse are represented by 

 Chrysotis finschi, C. albifrons, and^ Psittacula cyanopyga. 

 These all extend along the western flank of the mountains at 

 least as far as Alamos in Sonora, and in like manner may be 

 said to define the regional boundary on that side of Mexico. 

 So far as the central country is concerned, if we except 

 ^Rhynchopsitta pachyrhyncha, which is probably only found 

 on the Western Sierra Madre, Parrots do not occur nearly so 

 far north. The northern distribution of Parrots, thus sketched 

 out, is practically that also of the Trogonida?, Trogon amUguus 

 having a northern extension on either side of the mountains 

 precisely like that of the Parrots just mentioned. It is the 

 same on the eastern side with the Momotidse, Momotus 

 ccBruleiceps being found at least as far north as Monte- 

 raorelos, in Nuevo Leon. It is the termination, too, of 

 the Tinamidifi, and also of the Cracidie, with the exception 

 of Ortalis vetula sive maccalli, which goes a little farther 

 north and crosses the Rio Grande into Texas. Of Passeres 

 the same boundary limits Pachyrhamphus on both sides 

 and Pitylus celano on the east. From this it will be seen 

 that the line of demarcation between the two regions, so 

 far as the birds are concerned, is capable of being defined 

 with some precision, and will be found to coincide with the 

 northern limits of the forests. These on the eastern side leave 

 the coast a little north of Tampico, and continue in a narrow 

 belt along the eastern flank of the mountains in a nearly 

 northern direction almost to Monterey, On the western 

 side a similar state of things is found, and we meet with a 

 number of southern forms extending along the western slope 

 of the mountains as far as Alamos. 



'/ CyRTONYX SALLjEI. 



Cyrtonyx sallm, J. Verr. in Thompson's Arc. Nat. p. 35, 

 pi. 4. 



This species was fully described by Jules Verreaux ; but up 

 to the present time we have not been able to discover the 



