THE ACARIXA OR MITES. 



41 



Fig. 58. — Venter of Smaris. 

 (Author's illustration.) 



Lcptus, with the same type species, and Achorolophus Berlese are synonyms. 

 Many of our species will go in Atomus. Belaustium will include some of the 

 heavier, shorter legged species, which have more resem- 

 blance to Tromhidium. Our s'pecies have not been 

 apportioned but described under JRhyncholophus {Ery- 

 Ihracvs). Most of them, like E. simplex Banks (fig. 57), 

 are uniform reddish in color, but Erythraeus cinctipes 

 Banks has prettily banded legs, and {E .) Atomus maculatus 

 l^nmks (fig. 55) has several large pale spots on the dorsum, 

 while E. parvisetosus Ewing is almost wholly black. E\ving 

 has recorded finding a specimen of this species carrj'- 

 ing several of its larvse on its back, but perhaps they 

 were more probably red bugs. One of our species, E. 

 longipes Banks, has such extremely long legs that it 

 resembles a minute phalangid. Several species of the 

 genus Eatoniana occur in southern Europe and northern 

 Africa; they are remarkable on account of a plume of 

 long hairs on the hind legs. The South American genus 

 Cflec'i /; so ?n a differs irom. Erythraeus and Smaridia in having 

 two little buttonlike elevations near the tip of each metatarsus, as shown in figure 59. 



Family TROMBIDIID^. 



The "harvest mites," as they are popularly called, are recognized by the body 

 being divided into two portions, the anterior (cephalothorax) bearing the two anterior 



pairs of legs, the palpi, mouth parts, and eyes; the 

 posterior (abdomen) is much larger and bears the 

 two posterior pairs of legs. The mandibles (fig. 64) 

 are chelate; at least there is a distinct jaw or curved 

 spinelike process. They also differ from the allied 

 Rh^Ticholophidae in that the last joint of leg IV is 

 not, or very slightly, shorter than the penultimate, and in that the last joint of leg 

 IV is not swollen. The last joint of leg I (fig. 63) usually is swollen, often more so 

 than in the Rhyiicholophidse. They are always red in color, some, however, being 

 much darker than others. The body is covered with bristles or 

 feathered hairs, according to the species. The palpi are five-jointed, 

 quite prominent, often swollen in the middle, the penultimate 

 joint ending in one or two claws, the last joint (often clavate) 

 appearing as an appendage or "thumb" to the preceding joint. 

 The legs are seven-jointed; the tarsi terminate in two small claws 

 (fig. 62). The legs are clothed in the same manner as the body. 

 There are two eyes (fig. 61) upon each side of the cephalothorax, 

 quite frequently borne on a distinct pedicel. 



Along the median line of the cephalothorax there is commonly a crista (crista 

 metopica) or dorsal groove similar to that of the Rhjoicholophidse. This crista is 



Fig. 59. — Caeculisoma: Tarsus I. 

 (Original.) 



Fig. 60. — Egg of 

 Trom bidium. 

 (Author's illus- 

 tration.) 



Fig. 61.— Eye of Tromhidium. 

 (Author's illastration.) 



Fig. 62.— Claws of Tromhidium. 

 (Author's illustration.) 



enlarged at the middle or posterior end into a triangular area, called the areolae or 

 sensillae, in which are two pores from which arise bristles. Oudemans terms these 

 the pseudostigmata and pseudostigmatic organs; the latter are sometimes clavate 



