702 SCIENCE PROGRESS 



two species are distinct, and that consequently the rat is not a source of infection 

 to man. 



R. T. L. 



The Mosquitoes of North and Central America and the West Indies. By 

 Leland O. Howard, Harrison G. Dyar, and Frhderick Knab. 

 Vol. IV. Systematic Description (in two Parts), Part II. (pp. 525-1064). 

 (Washington, D.C. : Published by the Carnegie Institution of Washington, 

 1917.) 



This work, the second part of the systematic description, forms the concluding 

 volume of the authors' monograph of the American Mosquitoes. The subject- 

 matter is in direct continuation of that of Vol. III. It is equally comprehensive, 

 and the multitudinous and frequently complex details pertaining to this aspect of 

 the subject are marshalled and deployed in the same methodical sequence as 

 before. 



The authors relegate mosquitoes to a subfamily of the Culicidae, and consider 

 that the numerous forms fall naturally into two sections or tribes, the Sabethini 

 and Culicini. The Sabethini and later Culicine genera are treated in Vol. III. ; 

 the Megarhinines and Anophelines are grouped with the more generalised 

 Culicini and are discussed with the latter in the present work. In many instances 

 the authors' conceptions of Culicid genera differ widely from those of previous 

 writers. Owing, more particularly, to a careful and minute study of genitalic 

 and larval structure natural relationships have been more clearly demonstrated 

 and the limits of some of the older genera much extended. Hence, many 

 characters which formerly were deemed to be of generic value are rendered 

 invalid, and synonymic lists of appalling dimensions are unfortunately not 

 uncommon. This is specially noticeable in the case of the genus Aedes, where 

 some fifty additional names swell the list. However, if the authors'- interpretations 

 be correct, such results are unavoidable and must be accepted. 



Psorophora, the first genus dealt with, is enlarged to include Jantkinosoma 

 and that part of Theobald's genus Grabhamia typified by G. jamaicensis. The 

 structure of the female claws in Grabhamia is not considered of sufficient 

 importance to warrant separation from Janthinoso?na, which takes sub-generic 

 rank. The genus (Stegomyia) in which the well-known carrier of yellow fever 

 occurs is among those which have been incorporated with Aedes, but the generic 

 change of name consequent upon this is apparently not the only one necessary. 

 We learn that, in accordance with the laws of priority, the specific name of this 

 mosquito is now Aedes argenteus, since it was described as Culex argenteus by 

 Poiret in 1787, thus antedating the two names in common use. In the Anopheline 

 group the genera Anopheles and Ccelodiazesis are recognised ; the latter contains 

 a few forms, allied to our A. plumbeus, whose larvae live in hollow trees. 



The mosquito fauna of the regions covered by this monograph at present 

 consists of 398 species, and of these 380 are treated in detail in the systematic 

 volumes. The present volume deals with nine genera and 168 species, and 

 contains an appendix in which notes are given on some of the species described 

 too late to receive full discussion in the work. 



The issue of this volume must be a source of great satisfaction to the authors, 



and enables dipterists in general and students of the Culicidae in particular to 



offer their sincere congratulations to Messrs. Howard, Dyar, and Knab on the 



successful completion of a most laborious work. 



H. F. C 



