THE ACAKIXA OE MITES. 



39 



also at the anterior end, where it often includes a frontal tubercle. There are one or 

 two simple eyes on each side of the cephalothorax; they are always sessile. In one 



,-/ 



/ // <^ 



Fig. oi.—Erythxvs: a, Palpus; 

 b, mandibles; c, beak; d, trach- 

 eal pores; e, dorsal groove;/, 

 tarsus. (Author's illustration.) 



Fig. 55. — Atomus maculatus. 

 (Author's illustration.) 



?enus {Smaris) there are also two eyes close together near the middle of the anterior 

 margin. The palpi are prominent, five-jointed, the last forming a "thumb" to the 

 preceding, which ends in a claw. The mandibles (fig. 54) are slender, needle-like,, 

 and retractile, thus differing greatly from those of Trom- 

 hidium and forming the warrant for a separate family. 



The legs are commonly quite slender, the hind pah* 

 sometimes more than twice as long as the body. They 

 are seven-jointed and terminate in two small claws. The 

 last joint, or tarsus, is nearly always shorter than the pre- 

 ceding joint, and in the first and fourth pairs often swollen. 

 The body and legs are densely covered with bristles or 

 hairs, sometimes both. The hinder pair of legs are always 

 quite remote from the anterior pairs. The genital opening 

 is between the hind coxae, and the anal opening is usually 

 close l)ehind it. 



These mites are usually found on the ground, sometimes 

 in very hot situations, and run over the surface or on low 

 plants with great rapidity. Other species occur in moss or 

 under fallen leaves in woods, and one is abundant among 

 the rocks near the top of Mount AVashington. Several spe- 

 cies appear to live in colonies, but most are solitary in habit. 

 The eggs are deposited on the ground or under stones, often in clusters. The larva 

 (fig. 56) is a six-legged mite attached to insects. \Mien full fed it drops to the 

 ground and becomes quiescent, and after a varying time transforms to the adult. 



Fig, 56.— Leptus of 

 raen^ on a plant 

 (Original.) 



Eryth- 

 louse. 



