Fig. 71.—Pseudoscorpionida. Larca granulata, a native Illinois pseudoscorpion. Actual length 0.1 inch.
Phalangida
Daddy Longlegs, Harvestmen
Spider-like forms, each animal with a short, round body and four pairs of walking legs that in most species are very long, [fig. 72]. They occur chiefly in woods and may be found in numbers walking over foliage and logs; they are often found on bluffs and in shady places. They feed on decaying humus. A few Illinois forms that occur chiefly on bark have considerably shorter legs than the species that range more widely.
Fig. 72.—Phalangida. A common harvestman or daddy longlegs. Actual length of body 0.3 inch.
Araneida
Spiders
Varied and well-known animals, each with four pairs of walking legs and a body divided into a cephalothorax (which combines the head and thorax) and abdomen. The spiders present a tremendous variety of shapes, some being round and fat, like the black widow, Latrodectus mactans (Fabricius), [fig. 73], others being long and slender, mimicking ants. Others are crablike in shape; some that are long and slender are extremely rapid in their movements. Spiders appear practically everywhere. Certain species are domestic and are found only in houses. In Illinois the only poisonous species of any importance are the black widow spider, which is found in a variety of situations, and the recluse spider, Loxosceles reclusa Gertsch & Mulaik, which has been found in house basements in southern Illinois.
Fig. 73.—Araneida. Latrodectus mactans, the black widow spider. Actual length of body 0.4 inch.