pp. Bristles of the body not pectinate. q. In mills, stored foods, grains, etc. Third and fourth joints of hind legs scarcely twice as long as broad; abdominal bristles not unusually long; legs I and II of the male not unusually stout. T. AMERICANUS. qq. With other characters and habits. _T. lintneri_ (fig. 150 f) the mushroom mite, and several other species. mm. Cephalothorax with but two long distinct bristles (besides the frontal pair), but sometimes a very minute intermediate pair; tarsi I and II unusually short and not twice as long as the preceding segment. n. Tarsi with some stout spines. RHIZOGLYPHUS Clap. The species of this genus are vegetable feeders. Several occur in the United States. R. PARASITICUS and R. SPINITARSUS have been recorded from the old world, attacking human beings who handle affected plants. nn. Tarsi with only fine hairs. MONIEZIELLA Berl. The species of this genus, as far as known, are predaceous or feed on recently killed animal matter. Several species occur in the United States. M. (= HISTIOGASTER) ENTOMOPHAGA (fig. 152) from the old world has been recorded as injurious to man. gg. Genital suckers absent; integument with fine parallel lines. Parasitic on birds and mammals. h. Possessing a specially developed apparatus for clinging to hairs of mammals. LISTROPHORIDÆ. hh. Without such apparatus. i. Living on the plumage of birds. ANALGESIDÆ. ii. In the living tissues of birds and mammals. j. Vulva longitudinal. In the skin and cellular tissues of birds. CYTOLEICHIDÆ.