CLASSIFICATION 395 



localities, such as the Isle of Portland, and occurs, though less 

 commonly, all over the country in similar situations, and under 

 the loose bark of trees. It is half an inch in length, with a 

 chestnut-coloured cephalothorax and legs, and dull yellow abdomen. 

 A closely allied species, D. crocota, also occurs more rarely. 



Harpactes hovibergii is common in vegetable debris and under 

 decaying bark. It is about a quarter of an inch in length, of 

 slender form, with black-brown cephalothorax and clay-coloured 

 abdomen. The legs are yellowish and annulated. More than 

 forty exotic species of Bysdera and twenty-four of Harpactes 

 have been described. Another genus of the Dysderinae is Stalita, 

 which comprises three species, inhabiting the caves of Dalmatia 

 and Carniola. 



(ii.) The Segestriinae include two genera, Segestria and 

 Ariadna. 



Segestria senoculata occurs in England in similar localities 

 to those where Dysdera cambridgii is found. It is not nmch 

 smaller than that spider, and has a dark brown cephalothorax 

 and legs and a dull yellow abdomen, with a series of adder-like 

 diamond-shaped black markings along the middle. Two other 

 species have occurred on rare occasions in England, and twelve 

 more are recorded from the various temperate regions of the 

 world. 



Ariadna is the only Dysderid genus which invades the 

 tropical regions. It includes about twenty species. 



Fam. 12. Caponiidae. — This is a small family of three genera 

 and about twelve species, remarkable in having no pulmonary 

 sacs but five tracheal stigmata,^ and in the peculiar arrangement 

 of their six spinnerets, those which are ordinarily median being 

 in the same transverse line with the anterior ones. 



The single species of Caponia (C natalensis) inhabits South 

 Africa, while Caponina has two species in South America. These 

 spiders are eight-eyed, but the two median posterior eyes are 

 much the largest, and these alone are present in the remarkable 

 o-enus Hops, of which several species inhabit South America and 

 adjacent islands. 



Fam. 13. Prodidomidae. — This small family includes about 



1 According to Bertkau (in a letter to Simon, cited in Hist. Nat. cUs Ar. i. 

 p. 327), two pairs of linear stigmata under the anterior part of tlie abdomen lead, 

 to pulmonary sacs, but to tracheae. 



