12 



PSYCHE 



[February 



these genera is so extraordinary that I give it in detail in the following complete list 

 of genera: 



Sub-order Amblycera 



Family Gyropidae (found exclusively on mammals). 



Genus Gyropus, 7 species. 

 Family Liotheidae (found almost exclusively on birds). 

 Genus Latumcephalum, 1 species. 

 Genus Heterodoxus, 1 species. 



Genus Ancistrona, 2 species. 



Genus Nitzschia, 4 species. 



Genus Boopia, 5 species. 



Genus Trinoton, 10 species. 



Genus Laemobothrium, 24 species. 

 Genus Physostomum, 29 species. 



Genus Colpocephalum, 137 species. 

 Genus Menopon, 212 species. 



Sub-order Ischnocera. 



Family Trichodectidae (found exclusively on mammals). 



Genus Trichodectes, 45 species. 

 Family Philopteridae (found exclusively on birds). 

 Genus Eurymetopus, 1 species. 



Genus Philoceanus, 1 species. 



Genus Bothriumetopus, 1 species. 



Genus Kelloggia, 

 Genus Ornicholax, 

 Genus Nesiotinus, 

 Genus Giebelia, 

 Genus Ornithobius, 

 Genus Akidoproctus, 

 Genus Oncophorus, 

 Genus Goniocotes, 

 Genvis Goniodes, 

 Genus Lipeurus, 

 Genus Docophorus, 

 Genus Nirmus, 



1 species. 

 1 species. 

 1 species. 

 1 species. 



5 species. 



6 species. 

 19 species. 

 56 species. 

 63 species. 



181 species. 

 214 species. 



229 species. 



This really extraordinary disposition of species merits some special attention. 

 In the first place it is of interest to note that exactly the members of the pair of largest 



