410 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 species of 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. 
(vu.) The PoLtyrnaE include some 
ae Ae ee ae remarkable spiders, found in Africa and 
Mae 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. 
(vili.) 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 cephalothorax usually prominent at 
the angles. The type genus 1s Arcys. 
Fam. 24. Uloboridae.—The Uloboridae are ecribellate 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, 
ULOBORINAE, and MIAGRAMMOPINAE. 
Gi.) The DINoPINAE are a small group comprising only two 
genera, Dinopis and Menneus. The calamistrum is short, occupy- 
ing not more than half of the metatarsus. Twenty species of 
Dinopis and six of Menneus are scattered over the tropical 
regions of the world. 
(ii.) The ULoporinak include a number of spiders which have 
been described under several generic names, but are now considered 
to fall into two genera, Sybota and Uloborus. Sybota has only two 
