4IO ARACHNIDA ARANEAE CHAP, 



of the abdomen of a number of " sigilla," or somewhat seal-like 

 impressions arranged symmetrically, four forming a trapezium 

 in the middle, while the others are dis- 

 tributed round the border. 



There are about 200 8])eciesoi Gastera- 

 cantha, all natives of tropical countries. 



The spiders of the genus Micrathena 

 {Acrosoma) have a more elongate cephalo- 

 thorax, and sometimes the spines are ex- 

 ceedingly long, far exceeding the length 

 of the body proper. Among the less 

 spiny members of this group are some 

 remarkable mimetic ant-like forms. 



(vii.) The Poltyinae include some 

 Fig. 211.— Gasteracantha remarkable Spiders, found in Africa and 



mmax, 9 . . '- 



South Asia for the most part, though 

 sparingly represented in America and Oceania. They are generally 

 largish spiders, often with a very odd conformation of the abdomen, 

 which is generally much raised. The type genus is Poltys. 



(viii.) The Arcyinae, which are more characteristic of 

 Australia and the neighbouring islands, are a small group of 

 spiders, usually yellow with black markings, and with the 

 somewhat square -shaped cephalo thorax usually prominent at 

 the angles. The type genus is Arcys. 



Fam. 24. Uloboridae. — The Uloboridae are cribellate spiders, 

 with rather elongate cephalothorax, devoid of median fovea. The 

 cribellum is transverse and generally undivided. The first pair 

 of legs are usually much the longest. The metatarsi of the fourth 

 legs, in addition to the calamistrum, bear a number of generally 

 regularly arranged spines. The eyes are often situated on 

 tubercles. Three sub - families are recognised, Dinopinae, 

 Uloboeinae, and Miagkammopinae. 



(i.) The Dinopinae are a small group comprising only two 

 genera, Binopis and Menneus. The calamistrum is short, occupy- 

 ing not more than half of the metatarsus. Twenty species of 

 Binopis and six of Menneus are scattered over the tropical 

 regions of the world. 



(ii.) The Uloboeinae include a number of spiders which have 

 been described under several generic names, but are now considered 

 to fall into two genera, Sylota and Uloborus. Syhota has only two 



