LIST OF PLATES. 



PLATE I. 



PORTIONS OF CORNEA OF FLY'S COMPOUND 



EYE AND FLY'S FOOT . . . Frontispiece 



PLATE II. 



FLY'S "PROBOSCIS," AND PORTION OF ONE 



LABELLA OF SAME . . . . To face p. K)2 



PLATE III. 



MALE AND FEMALE GNAT 225 



PLATE IV. 



LARVA AND PUPA OF GNAT . . 2 3 



PLATE V. 



MALE AND FEMALE FLEA . . . . . . 258 



PLATE VI. 



BED-BUG . j.^-i ---- '- ' 2 86 



PLATE VII. 



TRACHEA OF SILKWORM AND WATER-BEETLE . 296 



