120 ANIMALIA ARTICULATA. 



all that has been said respecting the dangerous sting of these 

 animals, the consequence is not usually very serious, and acci- 

 dents, when occurring, have been occasioned by ignorant and 

 absurd treatment. M lian relates that the priests of Isis at Cop- 

 tos in Egypt trampled with impunity upon the very numerous 

 Scorpions of that town; and it is certain that the introduc- 

 tion of poison from the sting of the European animal is at- 

 tended with but trifling results. Certain naturalists pretend 

 that the Black Scorpion, living among the rocks of Africa, 

 will cause the death of a man, with its sting, in less than 

 two hours. It is not true that the animal turns its sting upon 

 itself when placed within a circle of fire. 



ORDER II. TRACHEARLE. 



Respiratory organs consisting in radiated, or ramified 

 tracheae, receiving air by two apertures or stigmata only ; no 

 veins, or arteries. From two to four eyes. One remark- 

 able family. 



FAMILY HOLETRA. 



Thorax and abdomen united in one mass under a common 

 epidermis; generally eight feet, sometimes only six. Two 

 remarkable genera. 



GENUS ACARUS. Mite. 



Sometimes chelicerse, but simply formed of a single forceps, 

 either didactyle or monodactyle ; sometimes a sucker composed 

 of laminae in the form of a lancet, and united. Sometimes in 

 place of a mouth is a mere cavity, without other apparent ap- 

 paratus. The most of these animals are very small, even 

 microscopic ; some are vagabond, and to be met with upon 

 stones, leaves, the bark of trees, in earth, water, flour, putre- 

 fied meat and old cheese ; others live parasitically upon the 

 skin, or in the flesh, of diverse animals; they have even been 

 observed in the brain and eyes of animals. 



