462 BIRDS OF THE GALAPAGOS ABCHIPELAGO—IilDGWAY. vol.xix. 



a little more than 30 miles of deeper water, and this of less than 2,000 

 fathoms dei)th. Its eastern edge, on the other hand, is decidedly more 

 than 200 miles distant from the nearest point on the coast of Ecnadoi 

 (a little south of the equator), while the deeper water between is more 

 than five times as wide as the northeastern " strait." 



If Dr. Baur's tlieory be correct, therefore, the Galapagos group and 

 Cocos Island were once culminating points of his "single large island,'' 

 and the nearest approach of this oceanic land area to the continental 

 area was toward the southern portion of Central America.' It is some- 

 what in favor of Dr. Baur's theory that at least one of the smaller land 

 birds of the Galapagos {Dendroica aureola) is common also to Cocos 

 Island ; but as tlie same species is said to occur also along the coast 

 of the maiidand, from Gorgona Island to the Gulf of Guayaquil, its 

 bearing on the subject loses some of its importance. We unfortunately 

 know very little as to the birds of Cocos Island, only four species of 

 land birds having thus far been collectecl, there.^ Of the three remain- 

 ing Cocos Island birds, one {Coccyzus/errugineus, Gould) is most nearly 

 related to a Central American and West Indian species, C. minor, 

 (Gmelin). The other two — Cocornis af/asshi, Townsend,-* and Xcsotric- 

 cus rUlgicayi, Townsend^ — are genera peculiar to Cocos Island, whose 



'That portion of the Colombian isthmus between the southern boundary of Costa 

 Rica and the Bay of Panama. 



•Cocos Island lies within the rain belt and supports an exceedingly luxuriant 

 vegetation from its summit down to the water's edge, numerous streams dashing 

 down its mountain sides into the sea. Undoubtedly it supports a much more varied 

 bird fauna than any of the Galapagos Islands, and iaterestiug if uot remarkable 

 forms remain to bo discovered there. Unfortunately it is difficult of exploration on 

 account of the density of the vegetation, which can only be penetrated by the aid of 

 a machete; but as Mr. Townsend, who made a brief landing there February -8, 1S91, 

 collected among four species of land l)irds two new and exceedingly distinct genera, 

 it is to be hoped that the unknown treasures which certainly await discovery may 

 tempt some adventurous naturalist to direct his efforts to a thorough exploration of 

 this island. 



Mr. Townsend has recently published a list of the birds which he ol>tained on 

 Cocos Island, in a paper with the following title: 



Bulletin of the Museum of Comparative Zoology | at Harvard College. | XXVII, 



No. 3. I I Reports on the Dredging operations off the West coast of | Central 



America to the (ialapagos, to the West coast | of Mexico, and in the Gulf of Califor- 

 nia, in charge of | Alexander Agassiz, carried on by the U. S. Fish Commis | siou 

 steamer Albatross, during 1891, Lieut. Commander | Z. L. Tanner, U. S. N., com- 

 manding. I XVII. I Birds from Cocos and Malpelo Islands, with notes on | Petrels 

 obtained at Sea. | By C. H. Townsend | [Published by Permission of Marshall Mc- 

 Donald, U S. Fish Commissioner.] | With Two CVdored Plates. | Cambridge, Mass., 

 U. S. A. : I Priuted for the :\Iu8eum. | July, 189.5. 



Pages 121-126; plates not numbered. 



'Cocornis, Townsend, Bull. Mus. Comp. Zool., XXVII, .July, 1895, p. 123. Type, C. 

 agaasizi, Townsend (Bull. Mus. Corap. Zool., XXVII, July, 1895, p. 123, colored plate; 

 Cocos Island ; U. S. Nat. Mus. ). 



■"JN^eso^ncc^s, Townsend, Bull. Mus. Comp. Zool., XXVII, July, 189.5, p. 124. Type, 

 A'. ntZ^fca//), Townsend (Bull. Mus. Comp. Zool., XXVII, July, 1895, p. 121, colored plate; 

 Cocos Island; U. S. Nat. Mus.). 



