THE CHELIFERIDJE. 



163 



PHRYXUS REXIFORMIS. 



occupied by the dorsal plate of the cephalothorax, and this has eight ocelli, of which two, as in the 

 Scorpions, are placed close to the middle Hue. The falces consist of two joints, with an apical 

 claw ; the true maxillary palpi are large and stout, and terminate either in a simple claw or in an 

 imperfect pincer, in which the movable finger is considerably shorter than the other ; while the second 

 palpi, or first pair of legs, are long and slender, and terminated by a finely annulated tarsus. The 

 three pairs of true legs are comparatively stout. Attached to the posterior end of the cephalothorax 

 is the abdomen, which is flat, slightly narrowed towards the base, and composed of eleven or twelve 

 segments ; it has 110 comb-like appendages at its base, and 

 the hinder extremity is not narrowed into a flexible tail 

 armed with a sting, as in the Scorpions, although in one 

 genus (Tkelypltouius) the last three segments are much re- 

 duced in size, forming a short tube, terminated by a long, 

 jointed filament. The respiration is effected by lung-sacs, 

 the stigmatic openings of which are situated near the hinder 

 margin of the second and third ventral plates ; the sacs 

 contain numerous lamellae (about eighty in some species). 



Although destitute of the formidable sting of the 

 Scorpion, the attacks of these creatures, which are mostly 

 of considerable size, are dreaded by the inhabitants of the 

 countries in which they occur. No doubt the pointed claw of 

 the falces is perforated and connected with a poison gland, 

 as in the true Spiders, and it is by means of these organs 

 that painful wounds are inflicted. In their general habits 

 the Phrynicla? much resemble the Scorpions, with which 

 they also agree in the tubular structure of the alimentary 

 canal. They are not numerous in species, and form only two 



principal genera, which, however, are represented in the tropical parts of both hemispheres, although 

 the species are most numerous in America. They are generally from an inch to an inch and a 

 half in length, but a species five inches long (TJielyphomis yiyanteus) has been described from 

 Mexico. This, however, includes the annulated tail characteristic of the genus Tkelyphonus, which 

 is often of considerable length. In the genus Phrynus, in which the tail is wanting, the second 

 pair of palpi are very long, sometimes three times the length of the body. The species of Phrynus 

 are viviparous. 



FAMILY III.-CHELIFERID^E. 



This family comprises a great number of little creatures, which, in appearance, are exactly com- 

 parable to minute flattened Scorpions that have lost their tails ; they are known as False Scorpions 

 and Book Scorpions. Like the Scorpions they have the first palpi developed into long didactyle 

 chelae, and the second pair in the form of legs, but their basal part forms no 

 part of the boundary of the mouth ; the falces (representing the antennae) are 

 much reduced, and the surface of the cephalothorax, which is often divided 

 into two parts by a transverse furrow, bears only one or only two pairs of eyes. 

 Behind the cephalothorax follows a broad, flat abdomen, composed of eleven 

 similar segments, and without any comb-like appendages at its base. Oil the 

 first two abdominal segments are placed two pairs of stigmata, opening, however, 

 not into lung-sacs but into regular tracheae, which give off branches to the 

 organs of the body in the same way as in the remaining families of the order, 

 and in the second segment is the opening of the sexual organs, close to which 

 are some silk glands, with the secretion from which the little creatures are said 

 to manufacture protective coverings for themselves when they are about to change 

 their skin, or to lie by for the winter. 



These little creatures, few of which exceed a sixth of an inch in length, are tolerably numerous, 

 and inhabit most parts of the world. They are generally of different shades of brown, and have the 

 limbs and frequently the cephalothorax paler than the rest of the body. Like the preceding groups 



CHELIFEH CAX- 

 CKOIDES. 



