Todd: Ornitiioiooy of TUhama Islands. 393 



strongly for (he point sought to be cinphasizerl. This is in striking 

 contrast with the case in the soutlicrn islands. 



Another point to which attention should be called is the occurrence 

 in the Bahamas, and especially in the northern and western islands, 

 of certain forms whose affinities are decidedly with others from Mexico 

 and Central America. Icterus northrnpi, which is very close to 

 Icterus prostheniclas, is a striking instance of this. In a recent paper 

 the present writer has gi\en reasons for believing that Geothlypis 

 roslrata is more closely related to certain Mexican species than to 

 G. trichas. Spindalis zena finds its nearest ally in Spindalis benedicti 

 of Cozumel Island. Some of the Bahaman species whose antecedents 

 are obviously Central American have spread over the group more 

 generally, as for instance Ncsophlox evelynce (allied to A", hryanlcc of 

 Costa Rica), Vireo crassirostris (very close to V. ochraceus), and 

 Ccereba bahamensis (near C. cahoti of Cozumel Island). All three of 

 these forms, it must be noted, have undergone more or less modification 

 upon entering the easternmost islands of the group, amounting to the 

 differentiation of a distinct species in the case of Nesophlox. 



To recapitulate: 



1 . The resident avifauna of the Bahama Islands is not homogeneous, 

 but ditifers to some extent at the respective extremities of the group. 



2. The avifauna of the northwestern islands resembles that of Cuba 

 more closely than dqes that of the southeastern islands. 



,1. There is a very considerable Central American element in the 

 Bahaman avifauna, more prominent in the northwestern islands. 



From the facts thus far set forth we may deduce certain inferences 

 regarding the derivation of the composite resident avifauna of the 

 islands. The one hundred species composing it may be divided into 

 five categories, as regards their specific antecedents and present 

 distribution. 



1. Species of more or less general distribution in tropical America, 

 and therefore of no especial value in predicating faunal alifinities. 

 Nearly all the water-birds belong to this class. 



2. Species identical with, or closely allied to, certain forms found in 

 Haiti, and which have doubtless reached the Bahamas from that 

 source, by way of Great Inagua. Examples of this class are Margarops 

 fuscatus fiiscatus and Tiaris hicolor bicolor. This element is not a 

 very large one, and in some cases has not si)read beyond the Inaguan 

 Fauna. 



