SPIDERS. 331 



The race of scorpions is of very ancient origin, for one 

 has been found in Silurian strata, and others nearly resem- 

 bling those now alive are found in the Carboniferous. 



Examples. Scorpio, Euscorpius, Buthus, Androctonus. 



Order 2. PSEUDOSCORPIONID^;. " Book Scorpions," e.g., 

 Chelifer, Chernes. 



Minute animals, most abundant in warm climates, under bark, in 

 books, under the wing covers of insects, &c. They are like miniature 

 scorpions, but without the long tail and sting. Their food probably 

 consists of the juices of insects ; the chelicerse are minute suckers, the 

 pedipalps like those of scorpions. The abdomen is broad, with 10-11 

 segments. They breathe by tubular tracheae, and have spinning glands. 



Order 3. PEDI PALPI. " Whip Scorpions," e.g., Thelyphonus, Phrynus. 



Small animals, found in warm countries. The abdomen is depressed, 

 well-defined from the thorax, and has 11-12 segments. The chelicerae 

 are simply clawed, but are poisonous ; the pedipalps are simply clawed 

 or else truly chelate. The first pair of limbs are like antennae. Respira- 

 tion by two pairs of lung sacs. In J^helyphomts there is a long terminal 

 whip. 



Order 4. PHALANGID^: (or OPILIONINA). " Harvest-men," e.g., 

 Phalangium. 



The small spider-like u harvest men " are noted for their extremely 

 long legs, by which they stalk slowly along avoiding the glare of day. 

 The broad six-segmented abdomen is not distinct from the thorax ; the 

 chelicerse are chelate ; the pedipalps are like legs. Respiration by 

 tubular tracheae. The harvest men are sometimes called daddy-long legs, 

 but we reserve that name for the crane fly (Tipula oleraced). Nor are 

 they to be confused with the troublesome " harvest bugs " (Trombidium 

 holosericeii-ni}, which are "minute red mites. The harvest men do not 

 trouble us, but feed on small insects. 



Order 5. SOLPUGID^E or SOLIFUG^, e.g., Galeodes or Solpuga. 



Active, pugnacious, venomous, nocturnal little animals, found in the 

 warmer parts of the earth. The head and abdomen are distinct from 

 the thorax. The thorax has three segments, the abdomen nine or ten. 

 The chelicerae are chelate, the pedipalps like long legs. The respiration 

 is by means of tubular tracheae. The segmentation of the thorax is 

 remarkable. 



Order 6. ARANEID^E. Spiders. 



Spiders are found almost everywhere upon the earth, and 

 a few are at home in fresh water. Most of them live on the 

 juices of insects, and many form webs in which their victims 

 are snared. They may be divided according to habit into 



