RENDAHL, BIRDS FROM THE PEARL ISLANDS. 9 



SO is this still more the case in the composition of the elements 

 of their bird life. 



Of the sixty-three species recorded from the islands the 

 following are in the main distributed in Panama and north 

 thereof but in Colombia represented by allied species or sub- 

 species: — 



Heterocnus cahanisi Camptostoma pusillum flaviventre 



Jlupornis ruficauda Elaenia martinica suhpagana. 



Ortalis cinereiceps Troglodytes miisculus inquietus 



Chlorostilhon assimilis Tanagra cana diacomis 

 Myiopagis placens accola 



Only occurring in Panama: 



(Cryptiirus soui panamensis) 

 Saucerottia edivardi 

 Myiophobus fasciatus furfurosus 

 Saltator albicolUs isthmicus. 



To t hese groups we may also add the following endemic 

 forms, being closely allied to forms of the main, which are not 

 stated south of Panama: — Coereba cerioclunis, Eamphocelus 

 dimidiatus limatus. 



Of the remaining species thirty-one belong to more or 

 less widely distributed species, found both North and South 

 of Panama. Of the endemic forms the following are allied to 

 such widely distributed forms: — Centurus seductus, Vireo- 

 sylva flavoviridis insulanus, and the doubtful Butorides vire- 

 scens margaritophilus, 



Eight species occur in Panama and south thereof, two 

 endemic birds, Elaenia chiriquensis sordidata, and Thryophilus 

 galbraithii conditus are allied to such forms. 



Thus the distribution of the forms represented in the 

 Pearl Islands precludes every idea of a closer connection with 

 or derivation from the Colombian fauna. Save for the two 

 above mentioned species all the birds of the islands are also 

 met Avith in the Panaman main and even if the occurrence 

 of endemic forms indicate an independence in certain species, 

 the species mentioned in the first groups absolutely indicate 

 a very close affinity even in forms, the characters of which 

 surely are of a late origin and very likely developed in Panama. 

 Either the bird fauna of the islands is still conveyed with new 



