."*• TIIK » ANAru.VS KNTOMOMMJIHT. 



BOOK NOTR-FS. 



CoNTRiBLri«)N> Towards a Monograph of thk Scolytid Hketles. 

 I. The (lenus Dendroctonus, by A. I). Hopkins, Ph. I). 



Tliis excellent monograph of tlic genus Dendroctonus was issued by 

 the United Stales Deiiartment of Agriculture as liulletin 17, part i, of the 

 Hureau of Kntoniology. It contains 164 text pages, eight full page plates, 

 and 05 text figures. Tlu" genus Dendroctonus had previously been dealt 

 with by Dr. Lecontc, in 1S6S and 1S76, and by Dr. Diet/ in 1S90. Now, 

 after a long study of a large amount of material, including the available 

 types. Dr. Hopkins has completely revised the classification, described 

 several new species, and the younger stages of many, and has allotted the 

 references in literature to their proper titles. In short, he has given us a 

 complete and scholarly monograph of the genus, lacking only the bionomic 

 features, which are promised for a future paper. 



The first portion of the work deals with the history of the genus, the 

 original description by Erichson, and a revised description by the author. 

 The last extends over sixty pages, and includes forty-four excellent figures. 

 The figures, with the exception of two, deal with the external and internal 

 anatomy of the adult and larva of D. vniens, and with the external char- 

 acters of the i)upa. This series of drawings is by far the finest yet 

 published on the anatomy of the Scolytid beetles, and will be of great 

 assistance in future descriptive work in the Scolytid;v. 



"In all of this anatomical work the object of the author has been to 

 acquire direct information on the facts as they exist in the subjects 

 examined ; such information to furnish a basis for the determination, 

 naming, description and illustration of the anatomical elements as 

 represented in the Scolytid beetles, and at the same time to serve as 

 a guide to the determination of further facts relating to insect anatomy in 

 general.'" 



Tlu- text (II ini, ixiitHni oi mc woik picseiils many i>uiiUs ul murh 

 interest to students of insert anatomy, too many even to mention in this 

 short review. 



The reversal of secondary sexual characters within the genus, referred 

 to on page 52, is particularly interesting, as is also the discussion of 

 " Progressive Modifications," with the accompanying plates of eyes, 

 antennx and tibixv 



