260 THE NATURALIST IN AUSTRALIA. 



globules of mercury. An alternative simile, and the one which is probably a more 

 correct interpretation of their adaptive significance, is their conspicuous resemblance 

 to web-entangled dewdrops. Masquerading under this delusive cloak, they would no 

 doubt escape the attacks of many enemies such as birds or predatory wasps, to 

 which they would be otherwise subject in the exposed positions they are wont 

 to occupy on their adopted webs. The egg cocoon constructed by this little com- 

 mensal spider is a very elegant structure, shaped like a Greek amphora, and mounted 

 on a slender pedicle, by which it is either attached to the web or to a convenient 

 point on the adjacent foliage. The contour of these egg cocoons, as illustrated in 

 Fig. 8 of Chromo-Plate IX., is also remarkably suggestive of that of the stalked 

 sheaths or loricse of various of the minute Flagellate Animalcules figured in the 

 third volume of the author's earlier published work " A Manual of the Infusoria." 



Several other species of Argyrodes were observed by the writer, more especially 

 in North Queensland. All of them possessed the same habit of sharing on friendly 

 terms the webs of larger spiders, but lacked the silvery lustre of the type above 

 described. The dimensions of two of these Argyrodes were more considerable than 

 those of the silver species, and they were both characterised by their more elongate 

 gibbous contours. Stalked egg cocoons of a somewhat narrower ovate shape than 

 that of the variety figured were observed attached in a hanging position to the 

 horizontal guy-suspended snare of a species of Linyphia that one of these types had 

 selected for its abode in Cape York Peninsula. The genus Argyrodes is widely 

 distributed, and many of its members are credited with contenting themselves with 

 anything but a peaceful and subordinate share of the web to which they attach 

 themselves. One species in particular, which is referred to in Dr. McCook's 

 Monograph of American Spiders, and upon which he has conferred the appropriate 

 title of Argyrodes piraticum, habitually kills and devours the constructor of the web 

 it elects to occupy and takes sole possession of it on its own account. 



The Spider, Arachnura Higgensii, represented by Figs. 9 and 10 of the above- 

 quoted Plate, is remarkable for the singular elongation of the hinder moiety of 

 its body, which, to a considerable extent, recalls the structural modification 

 distinctive of the Scorpions or higher Arachnida. This elongate extremity is not, 

 however, as in that group, composed of distinctly differentiated articulations, but is 

 uniform in character with the remainder of the body, and both flexible and also 

 retractile to about one-half of the length indicated in the illustration. As shown 

 in the profile view of the species suspended by its web, portrayed in Fig. 10, the 



