28 ENTOMOLOGICAL NEWS [Jan., '2O 



Gomphine Agriogomphus and to that of the Corduline Cordulephya that 

 he finds preserved the remains of a common primitive form of the Anisop- 

 terous wing and which, in addition to the similarity of front and hind 

 wings, offers him a starting-point for a phylogenetic arrangement of the 

 Libelluline genera. He has chosen to put the generic table in a form 

 "more difficult to use, but giving a truer presentation of the natural sys- 

 tem, rather than to construct a dichotomous table for mechanical identi- 

 fication," as the realization of the former idea seemed to him to be more 

 important than to help the beginner. It must be admitted that, in prac- 

 tice, the reference of an unfamiliar form to its proper group by this table 

 is not always easy. 



Very full bibliographical references for the genera and especially for 

 the species are given up to 1915, so that for this subfamily the catalogues 

 of Kirby and of Muttkowski are superseded by the present work. After 

 each reference under a species the locality or country to which that cita- 

 tion applies is given in parentheses, a very useful addition. The material 

 studied for this monograph is listed under the museums or collections 

 to which it belongs, so that the geographical distribution of any species 

 can only be ascertained by collating and rearranging these data a feature 

 which can not be praised. Special attention has been paid to pointing 

 out any differences found between specimens of the same species from 

 different localities, even where such are not given subspecific rank. 



Dr. Ris has rightly perceived that a most important task called for in 

 the execution of this monograph, where so many forms had already been 

 described, was that of critical comparison to determine the status of those 

 previously named and he has exercised this function throughout, not 

 hesitating to express in the supplement views different from those put 

 forth in some earlier fascicules. 



The typography is very clear. Dr. Ris's photographs of wings and 

 M. Menger's drawings of genitalia and other details are reproduced as 

 excellent half-tones in the text. The colored plates show entire insects 

 in most cases. The paper is of a finish correctly designated as elegant, 

 but, alas, with a weight which is serious when the fascicules are handled 

 together. 



The last words of the introduction to fascicule XVI, part 2, may be 

 freely rendered thus: "As I now give out this great work from my hands, 

 I am very conscious more so than at its beginning that it is not a 

 conclusion but a commencement, a foundation on which more can be 

 built, more easily and more safely than before the extensive material was 

 collected and sifted." For that collecting and sifting we offer our thanks 

 and our praise to the author, our hearty congratulations for his execution 

 of the "legacy" received from the great Belgian master. Only after we 

 have studied his work in detail, by comparisons with the insects of which 

 it treats, can we presume to fully appreciate its value. 



PHILIP P. 



