SPIDERS 



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Order 4. Phalangid.'e (or Opihonina). " Harvest -men," e.g. 



Phalangium 



The small, spider-like '' 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 constricted off from the 

 unsegmented cephalothorax ; the chelicerse are chelate ; the pedipalps 

 are like legs. Respiration is by tubular tracheae. The harvest -men 

 do not trouble^us, but feed on small insects. 



Order 5. Solpugid.e or Solifug/E, e.g. Galeodes or Solpiiga 



Active, pugnacious, non-venomous, nocturnal animals, found in 

 warm 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 large and chelate, the pedipalps like long legs. The 

 respiration is by means of tubular trachea. The presence of distinct 

 segments on the thorax is remarkable. 



Several other small orders of Arachnids must be recognised, e.g. 

 Palpigradi for a very interesting minute form, Kcenenia, with the last 

 two joints of the cephalothorax free, and with an abdomen of eleven 

 segments ending in a long-jointed whip. 



Order 6. Araneid^. Spiders 



Spiders are found almost every vvhere upon the earth, 

 and a few are at home in fresh water, e.g. Argyroneta, and 

 on the seashore, e.g. Desis, Desidiopsis. Most of them 

 Hve on the juices of insects, and many form webs in which 

 their victims are snared. They may be divided, accord- 

 ing to habit, into the wanderers who spin httle, and the 

 sedentary forms who spin much. 



The body of a spider is very distinctly divided into two 

 parts : the cephalothorax and the abdomen, connected by 

 a narrow waist. The chitinous cuticle varies in hardness, 

 hairiness, and colouring ; it has, as usual, to be moulted 

 as the spider grows. Thus the young garden spider moults 

 eight times in its first year. 



There are six pairs of appendages — 



1. The two- jointed chelicerae or falces, whose terminal joint or fang 

 bends down on the basal joint in " sub-chelate " fashion, and is per- 

 forated by the duct of a poison gland. 



2. The leg-like, usually six-jointed, non-chelate pedipalps, whose 

 basal joint helps in mastication, while the terminal joint in the male 

 expands as a reservoir for the spermatozoa and serves as a copulatory 

 organ. 



3-6. Four pairs of terminally clawed seven-jointed walking legs. 



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