hh. Third segment of the antenna not thickened at the base, second as long or longer than the third, rarely shorter. i. Posterior coxæ hinged (cardinate), if rarely rotating, the cuneus is severed, the membrane is one or two-celled, and the meso- and metasternum are composite. j. Ocelli absent, clypeus dilated toward the apex; hemelytra always short, membrane wanting. Species parasitic. Bed bugs, etc. CIMICIDÆ k. Beak short, reaching to about the anterior coxæ; scutellum acuminate at the apex; lateral margin of the elytra but little reflexed, apical margin more or less rounded; intermediate and posterior coxæ very remote. l. Body covered with short hairs, only the sides of the pronotum and the hemelytra fringed with longer hairs; antennæ with the third and fourth segments very much more slender than the first and second; pronotum with the anterior margin very _deeply sinuate_. CIMEX L. m. Sides of the pronotum widely dilated, broader than the breadth of one eye, and densely fringed with backward curved hairs; apical margin of the hemelytra nearly straight, rounded toward the interior or exterior angles. n. Body covered with very short hairs; second segment of the antenna shorter than the third; sides of the pronotum feebly reflexed, fringed with shorter hairs than the breadth of one eye; hemelytra with the commissural (inner) margin rounded and shorter than the scutellum, apical margin rounded towards the interior angle. The common bed bug (fig. 19h). C. LECTULARIUS Linn