3904 ARACHNIDA——-ARANEAE CHAP. 
seldom exceeding 2 mm. in length (the largest 4 mm), living 
among vegetable débris. Oonops pulcher, the only English repre- 
sentative of the family, is not rare under stones or in the débris 
at the bottom of hedges. It is a small brick-red spider, easily 
recognised by its six comparatively large oval eyes, which are 
pale-coloured, and occupy the whole of the caput. 
The minute spiders of this family were until recently over- 
looked by collectors in foreign countries, but now more than a 
hundred species have been described, belonging to some eighteen 
genera. Thirteen species inhabit the Mediterranean region, 
occurring especially on the African side. In several genera there 
is a “scutum” or hard plate on the abdomen. This is the case 
with Dysderina, which has a wide distribution, as have also 
Ischnyothyreus and Opopaea, and the non-scutate genus Orchestina. 
Fam. 10. Hadrotarsidae.—This family contains only two 
species, Hadrotarsus babirusa from New Guinea, and Gmogala 
scarabeus from Sydney. In general appearance they resemble the 
scutate Oonopidae, but they have eight eyes, curiously arranged, 
two large, somewhat triangular eyes being situated near the 
middle of the cephalothorax, and two groups of three small eyes 
on either side of the front part of the caput. These spiders are 
very minute. 
Fam. 11. Dysderidae.—WSix-eyed spiders, with long free 
labium, and long maxillae provided with a well-developed scopula. 
The cephalothorax is rather flat, and the abdomen is oval or 
cylindrical, the integument being smooth and usually rather soft. 
The palpal organ of the male is of simple structure. 
The Dysderidae are divided into two sub-families, DYSDERINAE 
and SEGESTRIUNAE, for the most part confined to temperate 
regions. 
(i.) The DysSDERINAE are easily recognised by a peculiarity of 
the sternum. Instead of being merely excavated along its border 
for the reception of the legs, its edge is folded round the coxae 
to meet the carapace, and thus forms a series of collars or sockets 
in which the limbs are articulated in perfect isolation from each 
other. These spiders vary considerably in size, and are gener- 
ally of a somewhat uniform coloration, never marked with vivid 
patterns. There are eight genera of this sub-family, two of 
which are represented in England. 
Dysdera cambridgii is not a rare spider under stones in rocky 
