98 Annals of the Carnegie Museum. 



Temperate Zone forms in common with the Colombian Andes, and 

 but five in common with both the Colombian and the Venezuelan 

 Andes together, while in thirteen cases (ten of which involve specific 

 differences) it possesses a distinct form of its own (one of which it 

 shares with the Venezuelan Andes.) There are also four groups in 

 which each region has a distinct form. (See Figure 8.) Consider- 

 ing the small number of forms found in this zone, this is a remarkable 

 degree of specialization, perhaps sufficient to entitle the region to be 

 set off as a distinct fauna. 



To account for the life and characteristics of the Temperate Zone 

 in the Sierra Nevada de Santa Marta we invoke the saiiie hypothesis 

 which we have already presented in detail when discussing the origin of 

 the fauna of the Subtropical Zone. The degree of specialization to 

 which more than half of the Temperate Zone forms have attained, 

 taken in connection with their small number in the aggregate, indi- 

 cates that they are the remnant of a fauna which must have reached 

 the extremity of its range by latitudinal extension, and then have been 

 cut off, resulting in isolation with subsequent differentiation. This 

 was probably true even in the case of such forms as Amasona, Gral- 

 laria, Scytalopus, Octhoeca, Henicorhina, and Diglossa, which are 

 represented in the zone below by allied forms. Of these the case of 

 Henicorhina leucophrys anachoreta may be cited as a typical example. 

 It is represented in the ' Subtropical by a specifically distinct form, 

 Henicorhina hilaris bangsi, which, however, is much more closely 

 allied to H. hilaris hilaris of Ecuador, and almost certainly entered this 

 region independently of the other. Indeed, their respective ranges 

 are not even contiguous. The forms of this zone (considered at 

 large) fall naturally into two groups, as pointed out by Dr. Chapman, 

 those obviously derived from Subtropical antecedents, and those which 

 are found at sea-level in southern South America, and which have 

 reached their present range in the northern part of that continent by 

 latitudinal extension. So far as our region alone is concerned, hovi- 

 ever, we believe that the Temperate Zone faiina is riiainly derivative, 

 and has reached its present ground by way of the Venezuelan Andes 

 and the western extension of the coast range. 



The " anomalies in distribution " to which Dr. Chapman alludes (on 

 page i6o of his work), in discussing the Temperate Zone of this region 

 involve the records for " Buarremon assimilis" and Myospiza "ma- 



