RELATIONS AND DIVISIONS OP TUB CLASS INSECTA. 13 
Termites or. White Ants, the Ephemeridse or May- 
flies, and the Psocidas, which latter often commit 
great ravages in collections of insects. 
The Orthoptera genuina consist of groups which for 
the most part are sharply defined ; the best known are 
the Blattidas or Cockroaches (erroneously termed 
“beetles ” by ordinary observers), the Forficulidm 
or Earwigs (which form the order Euplexoptera of 
Westwood), and the Grasshopper, Cricket, and Locust 
tribes j they also include the curious Leaf-insects and 
Walking-stick insects (Mantidse and Phasmidm). 
Rhynchota or Hehiptera. Mouth suctorial, consist- 
ing chiefly of an elongate articulate tube, which is 
more or less pointed at the end for piercing ; meta- 
morphoses incomplete. 
The first division, Heteroptera (or true Bugs), have 
the anterior wings horizontal, and composed of two 
parts, one coriaceous, and the other membranous; 
the Water-scorpion, the Water-boatman, and the 
curious spider-like Gerridae (which may be seen on 
almost all stagnant water in summer) are the best 
examples ; the ordinary Bed-Bug is a somewhat aber- 
rant member of the group ; in the Homoptera the wings, 
if present, are usually deflexed and meet at an angle, 
like the roof of a house ; the Cicada, the Cuckoo-spit 
insect, the Aphides, and the abnormal Coccidce, or Scale- 
insects, may be mentioned as examples. 
The Anoplura, or true Lice, are usually included in 
the Hemiptera as a degraded form, whereas the 
Mallophaga, or Bird-lice, as being furnished with 
mandibles, are classed with the Pseudo-Neuroptera. 
The Collembola ( Poduridce ) and the Thysanura (in- 
cluding Lepisma ) are, as above stated, extremely 
