. Agricultural zoology. Zoology. 196 ZOOLOGY. (Fig. 127). The last is the case with the mites, iu which, therefore, the characters of segmented animals can only be recognized in the limbs. In the true spiders (Fig. 124) the body consists of cepha- lothorax and abdomen. Arachnids have always four pairs of legs, which, in the true spiders, are attached to the cephalothorax, in the raites to the front part of the unsegmented body. The chief Orders belonging here are: (1) true Spiders (Ara- FiG. 124—A Spider neldo); (2) Scorpions (Scorpio- CSaiHcusscenicus). nido); (3) Harvestmen (Opilio- nida); (
. Agricultural zoology. Zoology. 196 ZOOLOGY. (Fig. 127). The last is the case with the mites, iu which, therefore, the characters of segmented animals can only be recognized in the limbs. In the true spiders (Fig. 124) the body consists of cepha- lothorax and abdomen. Arachnids have always four pairs of legs, which, in the true spiders, are attached to the cephalothorax, in the raites to the front part of the unsegmented body. The chief Orders belonging here are: (1) true Spiders (Ara- FiG. 124—A Spider neldo); (2) Scorpions (Scorpio- CSaiHcusscenicus). nido); (3) Harvestmen (Opilio- nida); (4) Mites (Acaridea). Only the last contains species of importance agriculturally. Order : Acaridea (Mites). Small arachnids, in which the cephalothorax and abdomen are fused together into one piece (Fig. 127). The just-hatched young have three pairs of legs, the adults, of course, four. Family: Acaridae (True Mites). Soft skin. No tracheae, no eyes. Legs short, often with a sucker at the end. Here belong the Cheese Mite (Acarus S'iro),the Meal Mite {TyroglyphusfariTwa), and several other species living in dead organic sub- stances; also— The Itch, or Mange Mites. These live as parasites on or in the epidermis, and cause the itch or mange (scabies) in man, as well as in several domestic animals. By means of the structure and habits three genera are distinguished :— 1. Digging, blood-sucking mange-mites living in the skin (Sarcoptes);. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Bos, Jan Ritzema, 1850-1928; Ainsworth Davis, J. R. (James Richard), 1861-1934. London, Chapman & Hall, Ld.
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectzoology, bookyear1894
