The Spiders of South Dakota

Spiders constitute the order of Araneida, which is one of the principal divisions of the class Arachnida. The Arachnida also includes scorpions, whipscorpions, pseudosscorpions, harvestmen, mites, and ticks. Some of the distinguishing characteristics of the Araneida are as follows: The head and thorax are consolidated into a cephalothorax. The abdomen is unsegmented and joined to the cephalothorax by a short narrow stalk. There are six pairs of appendages on the cephalothorax: chelicerae, pedipalps with heir basal masticulatory endites, and four pairs of walking legs