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THE AMEBIC AN NATURALIST [Vol. XL VII 



the Galapagos Island swallow, of which one is found on 

 two new world swallows and one is the Menopon rusticum 

 already mentioned as common to one old world, one new 

 world and one old and new world host. 



Mallophaga have been taken from three species of wrens, 

 Troglodytidae, of three different genera. Two species 

 of parasites have been taken from each host species, and 

 no one of these Mallophagan species occurs on more 

 than one host kind. 



The Cinclidae, or dippers, are represented in the list, 

 by two species of Cinclus, one from the old world and one 

 belonging to the new. One Mallophagan species, a Men- 

 opon, is common to both hosts, and each host species has, 

 in addition, another Mallophagan species, a Docophorus 

 in one case and a Nirmus in the other. 



The Mimidse, or mocking-birds, are represented by 

 seven species, of which five belong to the genus Nesomi- 

 mus peculiar to the Galapagos islands. The other two 

 are North American. There is one Mallophagan species 

 on each of the American mockers, and from one to as 

 many as eight on the various Galapagos Island hosts. 

 But the Mallophaga of the Galapagos Island mockers 

 are mostly species common to numerous other birds of the 

 islands, some of these birds being widely separated phy- 

 letically from the Mimida?. For example, the charac- 

 teristic Lipeurus bacillus of the pigeons has been taken 

 from one of the mockers. This apparently abnormal 

 condition has a normal explanation that we shall take up 

 in connection with certain still more conspicuous ex- 

 amples of the anomalies among the Galapagos records. 



The Turdidse, or thrushes, are represented in the list by 

 twenty-three species. Docophorus communis occurs on 

 nine of them. Menopon thoracicum is recorded from the 

 old world Turdus viscivorus and from Merula grayi and 

 Catharus gracilirostris from Costa Eica. The Sylviidae, 

 or old world warblers, are represented by five species, on 

 four of which Docophorus communis is the only parasite. 

 The Ampelida?, or waxwings, are represented by four 



