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THE AMERICAN NATURALIST 



[Vol. XLVII 



of two host species and the other two on a third. On one 

 species of Australian cassowary are found two Mallo- 

 phagan kinds, one of which is the same species as that 

 found on two of the South American rheas, while from 

 the African ostrich, Struthio camelus, are recorded two 

 parasite species, one of which is the same as that found 

 on the third rhea. Here, at the very outset, is a remark- 

 able case of distribution. Identical parasitic species on 

 hosts as widely separated, geographically, as Australia 

 and South America and Africa, but hosts all of a certain 

 degree of genealogic affinity. 



The order Tinamiformes, the tinamous of South Amer- 

 ica, curious birds, rather pheasant-like but presumably 

 not really pheasants nor true Galliformes of any kind, is 

 represented by eleven species in the Mallophagan host 

 list. Most of these tinamous are well parasitized, a spe- 

 cies of Nothura having four parasite species, one of 

 Crypturus five, one of Tinamus six, one of Rhynchotus 

 eight and another of Tinamus even nine parasite species 

 representing live genera, of which two are peculiar to the 

 group. Of the other Mallophagan genera found on the 

 tinamous two that specially characterize the pheasants 

 and other gallinaceous birds are, by odds, the most com- 

 monly represented. And this condition suggests another 

 interesting problem. Is it going to be possible to get 

 suggestions regarding the phyletic affinities of hosts from 

 the character of their parasitic fauna? Take, for ex- 

 ample, an order of birds troublesome to the ornithological 

 taxonomists. Will the evidence of the presence on mem- 

 bers of this order of certain parasitic genera character- 

 istic of another order indicate their affinities to this 

 second order? It does indeed seem, in the case of the 

 Tinamiformes and Galliformes, as if the evidence from 

 the Mallophagan distribution was in conformity with that 

 suggested by certain structural similarities in the two 

 groups. 



The great order Galliformes, including the pheasants, 

 partridges, quail, etc., is represented in the host list by 



