8 ARKIV FÖR ZOOLOGI BAND 13. N:0 4. 



virescens margaritophilus and Microphias grisea alticincta I 

 lack sufficient evidence for their definitive rejection, but I 

 think they are to be referred to resp. B. v. hypernotius Ober- 

 HOLSER (if even this form is quite distinct which I suppose 

 not) and M. g. inter media Cab. 



Of the remaining endemic forms the following are more 

 or less slightly differentiated from species of the main: — 



Of these, Centurus seductus is doubtless the most differen- 

 tiated, Ramphocelus dimidiatus limatiis being, however, also 

 a very distinct form. The other subspecies seem to me to be 

 more nearly allied to the species of the isthmus, though quite 

 distinct in itself. 



The endemic humming-bird, Phaethornis anthophilus hyali- 

 nus, is very interesting, it being stated both by Messrs. Thayer 

 and Bångs and by Mr. Ridgway to be a race of Ph. a. antho- 

 philus BouRC. from Colombia. Unfortunately I ha ve no ma- 

 terial of this species so I can only refer to what was stated by 

 these authors. 



The representative for the genus Microphias, however, 

 is identical with or if an island race very nearly allied to a 

 species occurring in Colombia and Venezuela, but not stated 

 from the main of Panama. Messrs. Thayer and Bångs also 

 f ound the Bananaquit of the islands not allied to the Panaman 

 species but to Coereba luteola from Colombia and Venezuela, 

 a view, the erroneousness of which I have shown in the fol- 

 lowing list of species (p. 49). 



The occurrence of these two Colombian forms in the Pearl 

 Islands is hardly to be taken as a sign of some closer affinity 

 between their bird faunas. If already the situation of the 

 islands speaks for a close accession to the Panaman main, 



