LARVAL FORMS OF COLEOPTERA 



well witli the one followed in Leng's catalogue. In those eases, how- 

 ever, in which the characters of the larvae suggest a different sys- 

 tematic position of the group to which they belong than do the char- 

 acters of their imagines, commentary remarks have been made in 

 footnotes. 



In a publication such as the present one in which the space limit 

 must be a rather determining factor only a few characters can be 

 used in the descriptions of the groups. As the field is new and 

 rather uncultivated it is unavoidable that misleading or impracti- 

 cable systematic characters have been introduced, or even that mis- 

 takes may have crept in. It is also realized that some of the figures, 

 especially those which were prepared many years ago, when the 

 authors were less familiar with the taxonomic value of the different 

 characters, are not entirely satisfactory; in fact, scores of old figures 

 have been discarded and new ones substituted. Frankly admitting 

 the many shortcomings of the paper, of which nobody is more aware 

 than the authors, it is nevertheless hoped that it may meet an evi- 

 dent desideratum in the entomological literature and encourage the 

 taxonomic study of the beetle larvae, a study which still is in its be- 

 ginning. 



For obvious reasons no attemiDt has been made to compile a full 

 bibliography, and such references to literature as are given will be 

 found in footnotes. Neither has a complete explanation of terms 

 been prepared, as the terms used in the kej's as a rule are defined in 

 the easily available "Glossary of Entomology" by John B. Smith, 

 published by the Brooklyn Entomological Society in 1906, or have 

 been defined and are in common use by modern entomological 

 writers, the present authors included. The very few new terms 

 found in the keys, such as " urogomphus, " meaning a tail-projec- 

 tion, instead of "cercus" or "pseudocercus, " and "raster," mean- 

 ing a rake, designated for the sj^inose region on the ventral side of 

 the last abdominal segments in Scarabaeidae, will readily be under- 

 stood through the examination of the figures themselves and the 

 corresponding explanations. 



Besides the strictly alternative characters of the keys, others, 

 guiding but not necessarily alternative, are given in parentheses. 



The generic and specific nomenclature used in the keys, and par- 

 ticularly in the explanations of plates, follows the one applied in 

 Leng's catalogue^^ for the North American larvae, in Reitter's cata- 



^*^ Charles W. Leng : Catalogue of the Coleoptera of America, 

 North of Mexico. 1920, with suppl. 1927. 



3 



