92 THE CANADIAN ENTOMOLOGIST. 



for the separation of the famihes and genera, and in some cases the 

 species. On account of its great size, the order Acarina (mites 

 and ticks) is necessarily dealt with more briefly than the other 

 groups, only the superfamilies being defined. Less space, for ex- 

 ample, is given to this group than to the Phalangida (Harvestmen), 

 a much smaller order. 



In chapters II. and III. the external and internal anatomy 

 respectively, of spiders, are discussed in considerable detail. A 

 special section of the former is given to the description of the dif- 

 ferent types of male pedipal})s, whose highly' complex structure is 

 of great taxonomic importance, and has been a subject of special 

 investigation by the author. Following the description of the 

 different kinds of spinning glands at the close of chapter III. is a 

 table, giving the names of these glands, with their number, the 

 position of their spinning-tubes, their distribution among the vari- 

 ous families and their functions. 



Chapter IV. is an account of the life of spiders, and deals with 

 this subject under a number of headings. Much attention is given 

 to the description of the different kinds of silk and their functions, 

 the types of webs, and to the structure and building of the orb 

 type of web. The account of the development is rather brief, the 

 embryological part being omitted altogether. This is, of course, 

 to be expected in a popular work, but the "Spider Book" is more 

 elaborate than popular works usually are, and we therefore think 

 that a brief outline of the early stages of development would not 

 have been out of place, considering the important bearing which 

 the development of som:e of the organs, such as the book-lungs, 

 trachea? and spinnerets have upon the phylogeny of the group. 



The systematic part of the book, comprising chapters V.-VII., 

 is enlivened by interesting notes on the habits peculiar to the 

 various families and genera, and by the numerous illustrations. 

 Brief descriptions of many of the commoner species are given, as 

 well as keys to all the families and genera inhabiting North America. 



The copious illustrations, which are largely photographic re- 

 productions of living or recently killed specimens and their webs 

 and nests, are scattered throughout the text, and give the book a 

 very attractive appearance by reason of their unusual excellence. 



Mailed March 13th, 1913. 



