434 CLASS ARACHNIDES. 



their two anterior tarsi are short, of the same size, and with 

 but few articulations. 



The others have the abdomen intimately united to the 

 thorax in its whole breadth, presenting at its lower base two 

 mobile laminae in the form of a comb, and terminated by a 

 knotted tail, armed with a sting at its extremity; their 

 stigmata are eight in number, uncovered, and disposed four by 

 four on each side, through the length of the belly ; their an- 

 tennce pincers (forceps) are terminated by two claws, the ex- 

 terior of which is mobile. They form the genus 



Scorpio, 



Which have the body long, and terminated abruptly by a 

 long and slender tail, composed of six knots^ the last of which 

 finishes in an arched and very sharp point, or in a dart, under 

 the extremity of which are tuo small holes, serving for an 

 issue to a poisonous fluid, contained in an interior reservoir. 

 Their thorax, in the form of a long square, and generally 

 marked in the middle with a longitudinal furrow, has at each 

 side, near its anterior extremity, three or two simple eyes, 

 forming a curved line, and towards the middle of the back 

 two other simple eyes approximated ; the palpi are very large, 

 with a talon at the end in the form of a hand ; their first 

 articulation forms a concave and rounded jaw ; at the origin 

 of each of the four anterior feet, is a triangular appendage, 

 and these pieces form, by their inter-approximation, the ap- 

 pearance of a labium with four divisions, the two lateral of 

 which maybe considered as kinds of jaws, while the two 

 others form the tongue ; the abdomen is composed of twelve 

 rings, comprehending those of the tail; the first is divided into 

 two parts, the anterior of \^■hich supports the sexual organs, and 

 the other the two combs. These appendages are composed' of 

 one principal piece, narrow, elongated, articulated, mobile 

 at its base, and furnished along its lower side with a series 



