RECENT LITERATURE. 255 



EECENT LITEEATUEE. 



A Monograph of the Jumjjing Plant-lice or Psyllidce of the Neio 

 World. By David L. Crawford. Pp. 182 ; plates 30. Smith- 

 sonian Institution, United States National Museum. Bulletin 

 85. Washington. 1914. 

 The author finding that classification of the Psyllidse on wing 

 venation alone was unsatisfactory, placing as it does closely related 

 species in different genera and even subfamilies, presents a new 

 system based largely on a study of structural characters other than 

 venation. 



The one hundred and seventy-five species in twenty-nine genera 

 here enumerated and described are arranged under six subfamily 

 headings, in the following sequence : — 

 Subfamily Liviinae. 



Tribe Liviini 1 genus (Livia), 5 species. 



,, Aphalarini ... 2 genera, 22 species. 



Subfamily Pauropsyllinse 3 genera, 15 species. 



,, Carsidarinae 4 genera, 13 species. 



,, Ceriacreminae 1 genus, 2 species. 



,, Triozinse 8 genera, 44 species. 



,, Psylhnae. 



Tribe Pachypsylhni... 3 genera, 9 species. 

 ,, Euphyllurini ... 2 genera, 6 species. 

 ,, Arytainini ... 3 genera, 18 species. 



,, Psyllini 2 genera, 41 species. 



Among other matters of interest treated in the introductory 

 pages (1-18), morphology is discussed in considerable detail. 

 An extensive bibhography is given. 



Pond Problems. By E. E. Unwin, M.Sc. Pp. xvi + 119. (Cambridge 

 Nature Study Series.) Cambridge : University Press. 1914. 

 This book supplies a series of lessons on Pond Life, intended for the 

 lower forms of Secondary Schools and upper standards of Elementary 

 Schools. It is above the average of such books, and we venture 

 to think that much of the work would be suitable for higher forms 

 in the Secondary Schools (if time could be found for it), and that any 

 entomologist, especially one who is given overmuch to collecting 

 simply, might study it with advantage. The aim of the series of 

 practical lessons and demonstrations is really to give some ideas 

 from actual contact with Nature " about environment, natural selec- 

 tion, and evolution." After showing how material should be obtained, 

 and making quite clear what an insect is, our author states that 

 "insects are really land animals," even though now in a compara- 

 tively few cases they may pass part of their life in the water. The 

 main object of the remaining lessons is, by practical observation and 

 experiment, to show how the adaptation to their new surroundings 

 is managed. The work concludes with useful appendices on material, 

 apparatus, the microscope and the making of microscope-slides, and 

 a short bibliography. The book, which is well got up, is illustrated 

 by forty-seven good figures, all, except two, from the author's draw- 



