1880.] OF THE GENUS ARGYRODES. 321 



this accretion forms no part (properly speaking) of the genital pro- 

 cess, though in what way it is formed it is difficult to say ; probably 

 it is an exudation from the genital organs, which hardens on coining 

 into contact with the air, and so adheres to the process in its outward 

 passage. I have noticed it iu several species ; but it is by no means 

 invariably found in all the individuals of a species. This abnormal 

 development greatly obscures its real structure, and considerably 

 lessens the value of the genital process oi Argyrodes as a criterion 

 (so valuable in general) of specific distinctness. 



Little appears to be known yet of the habits of this curious group 

 of Spiders. So far as observations have been made, they live in 

 their own irregular snares, spun among the outskirts of the snares of 

 large Epeirids. When travelling in Palestine some years ago, I met 

 with the type of the genus {Argyrodes epeirce, Sim.) in abundance 

 near the Sea of Tiberias, in the outskirts of the webs of Cyrtophoru 

 opunticE, Duf. ; its pretty little pear-shaped egg-cocoons were also 

 found suspended in the same position. Out of numerous cocoons 

 brought home, almost all were infested by a minute hymenopterous 

 parasite, the perfect forms of which emerged at different times during 

 the following summer. There does not appear to be any great 

 variety in the form of the egg-cocoon of the different species, those 

 of several which I have received being very nearly alike, excepting 

 in size. 



The known species of Argyrodes are now becoming rather nume- 

 rous — about 29 species, in addition to the 21 new ones here de^ 

 scribed, having been already characterized ; probably many more 

 will be discovered when greater attention is given to them by col- 

 lectors in exotic regions. Several of the most curious of those now 

 described were found among debris of the snares of some large 

 Epeirids, having evidently been bottled along with the latter but not 

 specially noticed or recognized at the time by the collectors. 



Fam. Theridiides. 

 Genus Argyrodes, Sim. 

 Argyrodes flavescens, sp. n. (Plate XXVIII. fig. 1.) 



Adult male, length rather more than 1 j line, that of the female 

 being rather over 2g lines. 



The fore part of the caput of the male is produced and elevated, 

 and is divided by a transverse cleft into two lobes, of which the upper 

 one is the strongest. The colour of the cephalothorax, as well as 

 of the palpi, falces, maxillae, labium, and sternum, is yellow, tinged 

 with orange ; the anterior portion of the lobes into which the caput 

 is produced is clothed with short coarse hairs. 



The eyes are placed four on the summit of the upper lobe of the 

 caput, forming nearly a square ; and on each side, at a considerable 

 distance below, a little behind the cleft which divides the two lobes, 

 is another pair, the eyes of which are contiguous to each other. 



The legs are long, slender, 1, 2, 4, 3, those of the first pair being 

 much tlie longest. They are of a deep blackish-brown hue, with the 



21=^ 



