Superfamily Argiopoidea 



Genus TIBELLUS (Ti-bel'lus) 



The members of this genus differ greatly in form from the 

 ordinary type of crab-spiders, the body being long and slender; 

 the cephalothorax is much longer than wide and the abdomen 

 is very long and nearly cylindrical. The posterior row of eyes 

 is strongly recurved, nearly forming a semicircle. 



These spiders are found on grass and on bushes; when at 

 rest the legs are stretched out longitudinally, two pairs forward 

 and two pairs backward. 



Only two species are known 

 from the United States. 



Tibellus duttonii (T.dut-to'ni-i). 

 — Our two species of Tibellus re- 

 semble each other so closely that 

 it requires careful observation to 

 separate them. The body is light 

 gray or yellow with three longitud- 

 inal brown stripes extending the 

 whole length of both the cephalo- 

 thorax and the abdomen (Fig. 620). 

 There is usually a pair of small 

 black spots on the abdomen near 

 the middle of the second half. 

 Sometimes the lateral bands on the 

 cephalothorax are broken into 

 distinct brown spots; and there 

 may be several dark brown spots 

 along the sides of the abdomen. 

 The male is about one third 

 inch in length; the female, about 

 one half inch. This species is distinguished from the Tibellus 

 oblongus by the following characters: The space between the 

 posterior median eyes is considerably less, sometimes only half 

 as great, as the space between one of them and the posterior 

 lateral eye of the same side. In the palpus of the male the short 

 embolus is very much curved. The second legs are more than five 

 times as long as the cephalothorax. The epigyna of the two 

 species are very similar. 



This is a very widely distributed species; and is common 

 on bushes and on grass. 



549 



Fig. 620. TIBELLUS DUITOXII 



