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THE AMEBIC AN NATURALIST [Vol. XLVIII 



mining factor in accounting for the host distribution of 

 the parasites, then it is also true that the distribution of 

 the parasites will indicate in some measure the genetic 

 relationships of the hosts, and that occasional aid in 

 determining the genetic affinities of birds and mammals 

 of doubtful relationships may be had from a study of 

 their parasitic fauna. In my paper already referred to 

 I have pointed out some suggestive cases of this sort in 

 connection with the birds and their parasites. 



In examining the conditions existing among the mam- 

 mals and their Mallophagan and Anopluran fauna, the 

 first necessity was the compilation of a complete record 

 or catalogue of mammalian hosts and their parasites, 

 together with the record of the actual locality of each 

 finding of parasites, together with a general record of the 

 geographic range of all the various hosts. This cata- 

 logue, or set of records, I have now completed, and 

 despite its meagerness compared with the similar cata- 

 logue of the bird hosts and their Mallophagan parasites 

 from which the notes for the former paper were drawn, 

 it contains enough records of interest to make worth 

 while a preliminary report on the condition obtaining 

 among the mammals and their parasites. 



It is unfortunate that, although there are nearly one 

 fourth as many mammal species as bird kinds, only about 

 one hundred mammals figure in the Mallophagan host 

 list, while Mallophagan parasites have been taken from 

 over eleven hundred bird species. Also, only one hun- 

 dred different Mallophaga have been taken from mam- 

 mals, while about fourteen hundred have been taken 

 from birds. Of the Anoplura, which are found only on 

 mammals, records have been made from about one hun- 

 dred host species, these records referring to just about 

 the same number of Anopluran kinds. Thus the mam- 

 malian host catalogue with its list of parasites is a short 

 one ; as far as it goes, however, it is thoroughly interest- 

 ing and suggestive. 



In working up the records I have used Trouessart 's 



