A somewhat larger member of the order occurs as a parasite upon a species of Dung-beetle (_Geotrúpes stercorárius_) which is vulgarly known as the Lousy Watchman. The beetle is black, shaded with purple, about three-quarters of an inch long, and is found under cow-dung. The mites cling pertinaciously to the under parts of the beetle, and can easily be seen with the naked eye. They are whitish, with the mandibles, the sucker, and two claws very distinct; and the palpi are unattached to the labium, or free. These mites form the species _Gam´asus coleoptrator´um_. Another species, _Gamasus telárius_, is the red spider of the greenhouse. _Trombid´ium fuliginósum_ (Pl. IX. fig. 37 _d_) is a common red spider of gardens. It is of a scarlet colour, appearing velvety from the presence of a dense coat of feathery hairs (fig. 37 _f_). The palpi of this mite are large, free, the last joint but one (Pl. IX. fig. 37 _a_) being furnished with a claw, while the last joint is obtuse, and resembles a lateral appendage. The mandibles (fig. 37 _b_) are furnished with a sharp curved claw. The legs are long, especially the anterior pair, and terminated by two claws, with a delicate sucker-like appendage (fig. 37 _c_). Another species of _Trombidium_, _T. holoseric´eum_, greatly resembling the last, is also found in gardens. It may be easily distinguished from the last by the club-shaped hairs (fig. 37 _e_) existing upon the body. The harvest-bug, which causes such irritation of the legs of persons who frequent corn-fields in the autumn, is also a species of _Trombidium_--_T. autumnále_. PLATE X. [page 133.] INSECTS. Fig. 1. _Atropos pulsotorius_: * natural size. 2. _Aphis_ of Geranium: _a_, foot; _b_, anal tube; _c_, antenna. 3. Scales on wing of Apollo-butterfly. 4. _Lithobius forcipatus._ 5. _Lithobius forcipatus_, head of: _a_, antennæ; _b_, mandibles; _c_, labial palpi; _d_, labium. 6. _Dytiscus marginalis_, head of larva. 7. Young larva of _Dytiscus marginalis_. 8. Pupa of Gnat (_Culex pipiens_). 9. Larva of Gnat. 10. Head of Gnat, male. 11. Head of Gnat, female. 12. _Coccinella 7-punctata_ (large Lady-bird), labium of. 13. _Coccinella 7-punctata_, mandible of. 14. _Coccinella 7-punctata_, labrum of. 15. _Coccinella 7-punctata_, antenna of. 16. Coccinella 7-punctata, maxilla of: _a_, palp; _b_, _c_, lobes of maxilla. 17. Head of _Musca domestica_ (House-fly): _a_, antenna; _b_, labial palpi; _c_, proboscis. 18. Head of _Stomoxys calcitrans_: 18 _a_, antenna. 19. Scales of insects: _a_, scale of _Podura_; _b_, of House-moth (_Tinea vestianella_); _c_, of _Podura_; _d_, of _Lepisma_; _e_, hair of _Podura_; _f_, scale of Cabbage-Butterfly (_Pontia brassicæ_). 20. Head of Cabbage-Butterfly: _a_, antennæ broken off; _b_, palp; _c_, tongue (antlia); _d_, club of antenna. 21. Head of human Flea (_Pulex irritans_), female (♀): _a_, palpi; _b_, maxillæ. 22. Flea of the Rat (_Pulex muris_), male (♂).