142 THE CANADIAN ENTOMOLOGIST 



This interesting species is easily distinguished from any 

 other North American species by its peculiar clypeus, which is 

 obliquely truncate in front of the clypeal suture, the latter being 

 strongly elevated, and also by the greatly swollen posterior femora 

 and enlarged tibiae. 



BOOK NOTICE. 



The Biology of Dragonflies (Odonata or Paraneur- 

 optera).— By R. J. Tillyard, M.A., (Cantab.) B.Sc. (Sydney), 

 F.L.S., F.E.S. Cambridge, The University Press, 1917. $4.50. 



Since the publication in 1893 of Dr. Calvert's excellent "Cata- 

 logue of the Odonata of Philadelphia, with an Introduction to the 

 Study of this Group of Insects," no general treatise on the biology 

 of the dragonflies has appeared, and as Dr. Calvert's work is now 

 long out of print and necessarily somewhat out of date, such a 

 treatise has been much needed. Mr. Tillyard's book fills this need 

 admirably. He has aimed "to present as full and complete an ac- 

 count of the biology of the Odonata as it is possible to offer in the 

 present state of our knowledge of these insects," and he has spared 

 no pains in carrying out this object. Every chapter bears the 

 imprint of a thorough assimilation and careful sifting of the avail- 

 able data and a great deal of new matter has been added from the 

 author's own extensive researches in many branches of the sub- 

 ject. With this wealth of material is combined a clearness and 

 directness of diction, which, with the abundance of good illustra- 

 tions and full glossary of technical terms should enable any biolo- 

 gist to follow the text without difficulty. A charm of novelty is 

 added by the author's familiarity with the Australian fauna, from 

 which he draws a large number of examples, in illustration of the 

 various phenomena described. 



Of the nineteen chapters ten are devoted chiefly to anatomical 

 matters, including those on the external features, the wings,- the 

 larva or nymph, and the various organic systems. These are fol- 

 lowed by chapters on a variety of subjects; embryology, coloration, 

 classification, zoogeographical distribution, the geological record 

 and bionomics; the last-named including a miscellaneous collection 

 of facts, relating to habits, food, enemies, economic value, etc. 



