ARTHROPODA. 131 



The elytra, coriaceous, or horny, when there are no inferior wings, 

 are frequently soldered together ; in one or two genera one over- 

 laps the other, and in some they diverge. Rarely the females 

 have neither wings nor elytra. The abdomen is connected by 

 its entire anterior portion to the metathorax. A small movable 

 piece attached to the coxa, called the trochantin, is sometimes 

 present. The anterior tarsi are absent in some Lainellicorns, as 

 well as the claw -joint in certain Curculionidae. 



The larvae vary enormously, from the shrimp-like active Dyticus 

 to the footless Curculionidae. In Meloe there are three larval 

 forms. 



The cockchafer (Melolontha vulgaris), the sacred beetle of the 

 Egyptians (Scarabceus sacer), shard or dung-beetle (Geotrypes 

 stercorarius), Spanish fly (Cantharis vesicatoria), glow-worm 

 (Lampyris noctiluca), and corn- weevil (Calandra granaria) are 

 members of this order, and, too well known in the larva state, 

 the turnip-fly (Haltica nemorum) and others of the same genus, 

 wire-worm (Agriotes lineatus), meal-worm ( Tenebrio molitor], the 

 church-yard beetle (Blaps mortisaga), and Colorado potato-beetle 

 (Doryphora decemlineata). Anobium domesticum has the common 

 name of " death-watch." 



Latreille long ago divided this order into four sections, under 

 which the families are even now almost universally arranged. It 

 is, however, a somewhat artificial system, as it would, if strictly 

 followed, widely separate closely allied groups. These sections 

 are dependent on the number of joints of the tarsi, thus : Pen- 

 tamera have five joints to all the tarsi ; Heteromera have five 

 joints to the four anterior tarsi only, the posterior having only 

 four; Tetrarnera have the tarsi four-jointed, and Trimera have 

 them three-jointed ; but exceptions occur in all. The last two 

 sections have frequently a minute penultimate joint [arthrium], 

 and have therefore been named Subpentamera, Pseudotetramera, 

 and Cryptotetramera, and Subtetrarnera, Pseudotrimera, and 

 Cyptotrimera respectively. The subsections were ranked as 

 families by Latreille. Stylopidse, frequently placed in a distinct 

 order [Strepsiptera, or Bhipiptera], are now pretty generally 

 regarded as a degraded type related to E-hipiphoridas and Me- 

 loidae. 



Above 80,000 species belonging to this order are described, 

 distributed under nearly 8000 genera. 



TRIMERA. 



Maxillary palpi securiform APHIDIPHAGA. 



Maxillary palpi filiform FUNGICOLA. 



K2 



