130 CALIFORNIA ACADEMY OF SCIENCES [Proc. 4th Ser. 



logical facts that the newer classification has revealed and em- 

 phasized. The remarkable degree to which these parasites are 

 broken up into natural groups that are strictly confined to 

 closely related groups of hosts, is now clearly evident, while 

 previously it was barely hinted at. The problem of their dis- 

 tribution is shown to be almost exclusively the problem of the 

 genetic relationships of their hosts. 



In 1908 there appeared, as a part of Wytsman's Genera 

 Insectorum, a catalogue, compiled by Dalla Torre, based upon 

 the work of Enderlein. This catalogue has proved of immense 

 value, but the knowledge of the Anoplura has increased so 

 rapidly since its publication that the additions and corrections 

 have now attained a bulk almost rivaling the original cata- 

 logue, and it therefore seems well that a new catalogue should 

 be issued. 



These changes and additions may briefly be summarized. 

 Since 1909 nine valid genera have been added to the list and 

 approximately 60 species have been described (the previous 

 catalogue listed 65, the present one lists 120). The position 

 of numerous species then in doubt has since been cleared up 

 and many of the question marks have been removed, this being 

 the case especially with the North American species described 

 by Osborn, almost all of which were then in doubt but have 

 since been cleared up. More significant, perhaps, than the de- 

 scription of new genera and species is the improved standard 

 of work that has been established. The magnificent "Mono- 

 graphic der Robbenlaiise" of Enderlein, in the report of the 

 "Deutsche Siidpolar Expedition," and the careful and critical 

 work of Fahrenholz, Cummings, and Neumann, form a splen- 

 did contrast to the superficial and often inaccurate work that 

 formerly prevailed. 



The synonymy of many of the hosts and some of the para- 

 site species is still badly tangled. The hosts have frequently 

 been referred to only by their vernacular names and when the 

 scientific names have been used they have sometimes been in- 

 accurate, added to which the instability of mammal nomen- 

 clature has not been conducive to clearness. The synonymy 

 of the North American mammals has in part been worked out 

 from the "List of North American Land Mammals in the 

 United States National Museum" (Miller, 1911), and, in ad- 



