HOLLAND: SIPHONAPTERA 587 



Though important theories on phylogeny have been published and classifica- 

 tions have been proposed, no really satisfactory arrangement is yet available. 

 The lack of agreement on relationships is well illustrated by the treatment of 

 Anomiopsylhis and related genera, which in three major works on North Ameri- 

 can fleas published between 1942 and 1947 appeared in three different families. 

 Jordan, of all students of fleas the most experienced and best equipped to pro- 

 pose a general classification, has not done so, except for a limited but nonetheless 

 important contribution in Smart (1948, rev. ed.). This neglect was in part de- 

 liberate, Dr. Jordan being reluctant to embark prematurely upon so difficult a 

 proceeding when new and unusual material was turning up continually all over 

 the world. Nevertheless, it was his intention to prepare a monograph of the 

 fleas of the world, but this was prevented by World War II. However, all is 

 not lost, and G. H. E. Hopkins and the Hon. Miriam Rothschild (daughter of 

 Charles) are now preparing a catalogue of the Rothschild collection largely ac- 

 cording to Dr. Jordan's views on the phylogeny of the group. All students of 

 Siphonaptera eagerly await the appearance of this work, which should provide 

 the most acceptable classification yet developed.* 



The flea fauna of many parts of the world is now fairly well known; that of 

 North America is particularly thoroughly investigated, in part because of con- 

 cern over sylvatic plague, which is the manifestation of Pasteurella pestis in 

 wild mammals. There have been numerous short papers by various authors, and 

 larger taxonomic works have been published by Ewing, I. Fox, Holland, Hub- 

 bard, and Traub, and a catalogue of literature by Jellison and Good. The fleas 

 of western Europe are fairly well known, and a group of siphonapterists, led 

 by loff, have made extensive contributions to the knowledge of fleas in the 

 U.S.S.R. Bedford, deMeillon, and Hopkins have published on African fleas, Liu 

 on those of China, and Cunha, Pinto, Guimariles, and others have made contri- 

 butions from the Neotropical region. Sharif of India has made important con- 

 tributions to morphology as well as to taxonomy, and Traub and Smit are cur- 

 rently publishing descriptions of fleas from many parts of the world. In 1946, 

 two papers of the greatest value to flea students were published. These were 

 Snodgrass's account of the skeletel anatomy of fleas, and da Costa Lima and 

 Hathaway 's catalogue to the literature on the order up to 1944. 



F. G. A. M. Smit of the British Museum at Tring recently circulated a list 

 of about sixty contemporary students of fleas. Less than a score of these are 

 really active in flea systematics, and most work at the species level. It is to be 

 hoped that a number of students will devote their efforts to considerations of 

 evolution and phylogeny of these insects so that a firm classification may ulti- 

 mately be achieved. 



It is now pretty well conceded that the fleas are divisible into two major 

 groups, usually considered as superfamilies, the Pulicoidea and the Ceratophyl- 

 loidea. These in turn may be divided into about 50 or more fairly well defined 

 natural groups of genera, the arrangement and constitution of which are the 

 basis for much present-day disagreement. Related species and genera may be as- 

 sembled fairly conveniently, but a number of cases of wrong association through 

 superficial resemblances brought about by adaptation remain to be sorted out. 



*The first volume (of five) of this work has been published (1953) since this manuscript was prepared. 



