December, '11] REVIEWS 565 



to the same species, it may be stated that frequently two and sometimes even three 

 different species of Ixodes have been taken from the same host at the same time 

 dm-ing investigations conducted by the Bureau of Entomology. The authors are 

 correct, in my opinion, in placing Ixodes sca-pularis and Ixodes californicus as varie- 

 ties of the European ricinus. There appears to be no valid reason for the mainten- 

 ance of Ixodes nigricans as a distinct species rather than as a variety of ricinus. 

 The material (one female from Death Valley, Calif.) considered by the authors to 

 be Ixodes pratti Banks is undoubtedly Ixodes kingi Bishopp, as is clearly indicated 

 by the description (of the female) and the illustration. This mistake was brought 

 about by the inclusion by Mr. Banks of two distinct species ' in the material consi- 

 dered Ixodes pratti by him. It might be stated here that Mr. Banks' description 

 of the male of Ixodes pratti is based upon the male of Ixodes ricinus var. scapularis. 

 Hence, the description of neither sex as given by Nuttall and Warburton applies 

 to Ixodes pratti. 



It is to be regretted that the authors did not have at hand a larger series of a num- 

 ber of the species discussed, to be used in the study of variation and correlation. 

 Although in many of the species but very few or only single specimens have been 

 collected, it would seem that larger series of other species might have been procured 

 for study. 



The authors consider that there are 51 valid species and 10 valid varieties and sub- 

 species of Ixodes. Twenty-one species and two varieties are recorded from North 

 America, this being a greater number than from any of the other continents. From 

 this list, Ixodes canisuga should be stricken as it does not occur in North America. 

 The authors misquote Mr. Banks on this point (page 214). 



The greater portion of that part of the work dealing with biologies of Ixodes is 

 devoted to Ixodes ricinus. Much of this matter is compiled from other authors. 

 Brief biological notes (mostly compiled) relating to Ixodes ricinus var. scapularis, 

 Ixodes angu^stus, Ixodes pilosiis, Ixodes canisuga and Ixodes pv^lus are presented. 

 The assemblage of these biological data will be found helpful particularly as they show 

 how meager is the published information on Ixodes. This may tend to emphasize 

 the need of more exhaustive and accurate investigations on the biologies of this 

 interesting group. 



As appendices are reprinted two papers previously pubhshed in Parasitology: 

 "The Process of Copulation in Ornithodoros moubata" by Geo. H. F. Nuttall and 

 Gordon Merriman and "On the Adaptation of Ticks to the Habits of their Hosts" 

 by Geo. H F. Nuttall. F. C. Bishopp. 



The Importation into the United States of the Parasites of the 

 Gipsy Moth and the Brown-Tail Moth: A Report of Progress, with 

 some Consideration of Previous and Concurrent Efiforts of this 

 Kind, by L. O. Howard and W. F. Fiske, U. S. Dep't Agric, Bur. 

 Ent., Bui. 91, pp. 1-312; plates 28 (several colored) and numerous 

 figures, 1911. 



The work with parasites of the gypsy and brown-tail moths has been continued 

 for some six years and has already resulted in some most valuable contributions to 

 knowledge and important modifications in laboratory practice. The above publi- 

 cation is a noteworthy paper on insect parasitism, based on an extended study of 



iSee Bishopp, "On Some New North American Ixodidas with Notes on Other 

 Species," Proc. Biol. Soc. Wash., Vol. XXIV, page 203. 



