TRACHEARI;E. 317 



prey through their cheliceree and jaws. They are particularly fond of the eggs 

 of Spiders and of Insects. 



The wound occasioned by the sting of the europceus is not usually dangerous. 

 That of the Scorpion of Souvignargues, of Maupertuis, of the species which I 

 have named Roussatre (pccitanus), and which is larger than the preceding one, 

 according to the experiments of Dr. Maccary courageously tried upon himself, 

 produces serious and alarming symptoms; the older the animal the more active 

 seems to be the poison. The remedy employed is the volatile alkali, used 

 externally and internally. There are several species. 



ORDER II. 

 TRACHEARm 



THK Arachnides which compose this order differ from those of the preceding 

 one in their organs of respiration, which consist of radiated 

 or ramified tracheae*, that only receive air through two 

 stigmata, in the absence of an organ of circulation ; and in 

 the number of their eyes, which is but from two to four. 

 The want of sufficiently general anatomical observations, 

 has prevented the limits of this order from being rigorously 

 determined. Some of these Arachnides, the Pycnogonides 

 for instance, exhibit no stigmata ; their mode of respiration 

 is unknown. 



The Trachearia? are very naturally divided into those 

 which are furnished with chelicerse, terminated by two fingers, one of which 

 is moveable, or by one that is equally so; and into those where these organs are 

 replaced by simple laminae, or lancets, which with the ligula constitute a 

 sucker. Most of these animals, however, being very small, great difficulties 

 necessarily accompany these investigations, and it is readily perceived that 

 such characters should only be resorted to when it is impossible to avoid it. 



FAMILY I. 

 PSEUDO-SCORPIONES. 



IN this family we find the thorax articulated, its first segment much the 

 largest, and resembling a corselet; the abdomen is very distinct and annulated, 

 and the palpi very large and in the form of legs or claws. There are eight 

 legs, with two equal hooks at the extremity of the tarsi, the two anterior ones, 



* The tracheae are vessels which receive the aerial fluid and distribute it to every part 

 of the interior of the body, and thus remedy the want of circulation. 



