GENERAL CLASSIFICATION 



Insects belong to the phylum Arthropoda, a group of animals having 

 jointed bodies and jointed legs. In the same phylum are to be found 

 the following classes : 



1. Crustacea. — AYater and land animals, with five or more pairs of 

 legs; two pairs of antenna'; and hard exoskeleton ; head and thorax 

 united. Examples: crabs, lobsters, crayfish and sowbugs. 



2. Arachnida. — Land forms; antennae absent; four to eight legs, 

 bead and thorax united. Examples : scorpions, solpugids, spiders, mites 

 and ticks. 



3. Malacopoda.— Land forms; body worm-like with numerous legs. 

 Very peculiar animals which are seldom met with. Example : 

 Peri pat us. 



■i. Diplopoda. — Land forms; body long, cylindrical, chitinized, many 

 segmented ; legs short, attached close together on the ventral surface, 

 usually two pairs to a segment ; antenna? sbort. Examples : millipeds 

 or thousand-legged worms. 



5. Symphyla.— Land forms; body small, slender, rather flattened 

 with soft whitish integument, many segmented ; twelve pairs of legs 

 in adults, less in young, single pair to a segment, attached wide apart 

 near sides, no poison jaws present: antennae quite long. Example: 

 the lima bean symphylid. 



6. Chilopoda. — Land forms; body long, flat, many segmented, some- 

 what chitinized; fifteen or more pairs of legs in adults, a single pair 

 to a segment, attached wide apart, first pair modified into poison 

 jaws; antenna? quite long. Examples: centipedes. 



7. Insecta or Hexapoda. — Aquatic and terrestrial, but primarily the 

 latter. Bod}' of the adults divided into three distinct regions: head, 

 thorax and abdomen. Adult forms with six legs. Many are winged. 

 Transformations or metamorphoses occur in all except the lowest 

 order, Aptera, which lias only primitive transformations. Examples: 

 insects. 



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