THOMBIBIUM. ARACHNIDES. 205 



eyes two, on a peduncle on each side of the thorax ; legs 

 elongate, filiform, the tibiae and tarsi two-jointed, and termi- 

 nated with a bent claw. 



S. rubens, Lat. Body pale red ; legs of a lighter colour. Inhabits 

 Europe, in moss at the roots of trees Sup. Encyc. Brit. i. pi. 23. 



FAMILY IV. ACAEIDES. 



The Acarides differ from the Phalangitze in the structure of the mouth. Their 

 body is oval or globular, of a soft consistence, and so small as to appear to the un- 

 aided sight like a simple moveable atom. The greater part have two pointed, 

 filiform and projecting palpi; the eyes are very small; the feet, to the number of 

 eight, rough with hairs, and terminated by two or three hooks, fixed in many on a 

 pedunculated and moveable vesicle. Some are found among provisions, as farina, 

 dried meat, and old cheese ; others on putrid animal substances, often on leaves, 

 and under the bark of trees ; while others are parasitical on the skin and flesh of 

 various animals ; and are, it is supposed, the cause of certain diseases. 



Gen. 11. TROMBIDIUM, Fab. Acarus, Lin. 

 Eight feet, proper for walking ; two projecting palpi, pointed at 

 the end, with a moveable appendage or kind of toe under the 

 extremity ; body divided in two parts, of which the anterior 

 portion is very small, and carries the first two pairs of feet, 

 the mouth, and the eyes ; mandibles with forceps ; two eyes 

 on a fixed peduncle ; body square, depressed. 



T. tinctorium, Lat. Body subquadrate, reddish, very tomentose and 

 hairy ; the hairs setaceous, elongate, and bearded. Inhabits Gui- 

 nea. Lat. Gen. i. 145. 



Gen. 12. ERYTHILEUS, Lat. 



Body without divisions ; eyes sessile ; palpi with the moveable 

 appendage subcheliferous ; hinder legs longest, then the first. 



E. phalangioides, Lat. Legs very long, the last joint broad, com- 

 pressed ; body obscure red, with a dorsal band of orange yellow. 

 Inhabits Europe, running on the ground with great agility. 

 Lat. Gen. i. 146. 



Gen. 13. GAM ASUS, Lat. 



Eight feet, proper for walking ; mandibles of a single joint, che- 

 liferous ; palpi projecting and filiform ; body depressed, the 

 skin of the back partly or entirely coriaceous. 



G. coleoptratorum, Lat. Coriaceous parts of the back fuscous ; an- 

 terior pair of legs a little longer than the hinder ones. Inhabits 

 the dung of horses, oxen, &c. often on the bodies of Scarabei. 

 Lat. Gen. i. 147- 



G. marginatus, Lat. Ovate, brown, coriaceous, the sides alone mem- 

 branous and whitish ; anterior legs nearly twice the length of the 

 body. Inhabits dung and dead animals Lat. Gen. i. 148. 



Gen. 14. CHEYLETUS, Lat. 



Organs of manducation forming a thick, projecting, and coni- 

 cal beak; palpi short, thick, their points falcate; body oval. 



