118 SPIDERS [CH. 



such of the large Aviculariidae as have been examined 

 have been all alike. 



There is in some spiders a spinning organ, not to 

 be found in Epeira, which deserves a passing notice. 

 It does not take the place of spinnerets, of which the 

 usual three pairs are present, but it is situated in 

 front of them, and only occurs in the female of the 

 species. Its peculiarity is that the silk does not 

 emerge from projecting spools ; but through fine 

 holes in a sieve-like plate, called a cribellum, which 

 is flush with the surface of the abdomen. It has no 

 mobility, therefore, and the threads from it have to 

 be combed out and distributed by the spider's hind 

 leg. For the better accomplishment of this purpose 

 there is a special comb of stiff hairs or bristles, called 

 a calamistrwm, on each of the fourth pair of legs. 



The web of these spiders is not unlike that of 

 Agelena, but of a rather finer texture, and it can be 

 seen, on magnification, to consist of an irregular 

 ground- work over which have been spread wavy 

 bands of excessively fine silk, combed out from the 

 orifices of the cribellum glands. Some of these 

 cribellate-spiders, of the genus Amanrobius, are not 

 uncommon in our cellars and out-houses ; their bodies 

 are of stouter build and their legs much shorter than 

 those of the common house-spider. 



We have no space for anything approaching a full 

 description of the anatomy of spiders, but there is one 



