Sub-family 1. Libellulidæ or Libellulines. Sub-family 2. Cordulidæ or Cordulines. Sub-family 3. Æschnidæ or Æschnines. Sub-family 4. Gomphidæ or Gomphines. Family 2. Agroninæ or Slender Dragon Flies. Sub-family 1. Agronidæ or Agronines. Sub-family 2. Calopterygidæ or Calopterygines. TRIBE II.--SUBULICORNIA. Family 3. Ephemeridæ or Day Flies. TRIBE III.--PLECOPTERA. Family 4. Perlidæ or Stone Flies. TRIBE IV.--CORRODENTIA. Family 5. Psocidæ or Book Mites. Family 6. Embiidæ or Agile Mites. TRIBE V.--SOCIALIA. Family 7. Termitiæ or White Ants. TRIBE VI.--PHYSOPODA (or Thrips). Family 8. Tubulifera. Family 9. Terebrantia. TRIBE VII.--MALLOPHAGA (or Bird-lice). Family 10. Philopteridæ. Family 11. Liotheidæ. TRIBE VIII.--THYSANURA (or Bristle-tails). Family 12. Lepismidæ. Family 13. Campodeidæ. Family 14. Japygidæ. TRIBE IX.--COLLEMBOLA (or Spring-tails). Family 15. Smynthuridæ. Family 16. Papyriidæ. Family 17. Degeeriadæ. Family 18. Poduridæ. Family 19. Amouridæ. SUB-ORDER 1.--PLANIPENNIA. The _Planipennia_ contains the most typical forms of the _Neuroptera_. This sub-order is subdivided into six families, four only of which contain representatives in the British Isles. They are most abundant in the tropical parts of the world, where also the most handsome and curious forms occur. [Illustration: Fig. 43.--Myrmeleon Formicarius.] _Family 1, Myrmeleontidæ._--The Ant Lions are the most familiar and important members of this family. The common Ant Lion (_Myrmeleon europæus_), which is abundant in sandy places in the south of Europe, is a slender and elegant creature, with large finely reticulated rings. The _larva_, to which the name of "Ant Lion" properly belongs, is of a stout form and a greyish-yellow colour, covered with warty processes and with hairs. Its food consists of ants and other small insects, which it captures by a singularly ingenious arrangement, namely, by means of a funnel-shaped pitfall which it constructs in the sand, and at the bottom of which it lies. When any unfortunate insect ventures too near, the Ant Lion sends up a shower of sand, and the victim in its consternation falls down the pit, where it is speedily seized and devoured. Other species of ant lions are known to occur on the continent of Europe, but none hitherto have been discovered to inhabit this country. [Illustration: Fig. 44.--Myrmeleon Larva.] [Illustration: Fig. 45.--Nemoptera Coa.] _Family 2, Hemerobiidæ._--The second sub-family contains the Lacewing Flies, many representatives of which occur in the British Isles. They are among the most elegant and beautiful of the _Neuroptera_.