10 INTRODUCTION. 



HOW TO ARRANGE THE COLLECTION, &c. 



In arranging the collection it is best to commence by 

 naming the species which we know, and then to put 

 aside those belonging to easily distinguished groups, 

 such as the Clcindelidce, Carahidce, Melolonthini, 

 Curculionidce, and Longicornia. If we do not know 

 what family to refer a beetle to, we must count the 

 number of joints of the tarsi, and so find out which 

 section each beetle belongs to. 



Those which have five joints to all the tarsi belong 

 to the Pentamera, which includes the Cicindelidce, 

 Carahidce, Dytiscidce, Staphylinidw, Melolonthini, and 

 many smaller families, in some of which the number of 

 joints is not constant, as is the case exceptionally in 

 all families. Next pick out those which have five 

 tarsal joints on the first and second pairs of legs, but 

 only four on the posterior pair. These are the 

 Heteromera, and include the Tenehrionidce, Melan- 

 dryidcB, LagrUdce, Alordellidce, Cayitharidce, &c. Then 

 come those which have only four joints to all the tarsi 

 — the Tetramera, to which belong the Curculionidce^ 

 Longicornia, and Chrijsomelidce, Whilst the fourth 

 section, the Trimera, in which there are only apparently 

 three joints to all the tarsi, includes the CoccinellidcB 

 and Paelajyhidce, &c. 



When the specimens have been sorted into these 



