542 



ARACHNIDA— ORDER ARANEIDA. 



Order VI. — Araneida (Spiders). 



The Araneida, or Spiders, are a very extensive group, with the usually un. 

 jointed abdomen well separated from the cephalothorax ; strong mandibles; 

 spinning glands ; and breathing with lungs and tracheae or with trachea? 

 alone. There is a variable number of eyes. They have been divided into 

 many families differing much in habits. They are very ferocious, and will 

 often kill and eat each other, but are much exposed to the attacks of birdi 

 and carnivorous insects, many sand-wasps provisioning their nests chieiy 



Fig 17. — Harvest Man (Liohunwn religiosum Simon). Nat. size. 



with spiders. As they cannot be domesticated, owing to their cannibalistic 

 propensities, their silk cannot be collected in sufficient quantities for com- 

 mercial purposes ; but spider's web has been recommended as a useful 

 application to stop bleeding. There are many kinds of spiders in various 

 countries the bite of which is said to be dangerous to man. 



Family I. — Theraphosid^. 



This family is distinguished from all the remaining spiders by the possession 

 of four lungs and only four spinnerets (except in Atypus, etc., which have 

 six) ; the remaining spiders having only two lungs (or two lungs and some- 

 times two trachete also) and six spinnerets. These characters are sometimes 

 used to separate the spiders into two main sections, the Tetrapiieumones, 

 including only the Theraphosidce (formerly called Mygalidce), and the 

 Dipneumones, including, the remaining spiders. 



The Theraphosidcx. are further remarkable for their large size, very hairy 



legs and bodies, and hard polished poison-fangs. Some of the larger species 



attain a length of from two to four inches, and spin a dense white web, in 



which birds as large as finches are sometimes entangled. This was first 



recorded by Madame Meriaii two centuries ago. It was 



Bird-catohing doubted, but has since been confirmed by Bates in his 



Spiders. " Naturalist on the Amazons," i. pp. 160-162 ; and by other 



observers. Bates further adds that the hairs of these large 



spiders are excessively irritating to the skin ; and lastly, " Some Mygales are 



of immense size. One day I sa\v the children belonging to an Indian family 



who collected for me, with one of these monsters secured by a cord round 



