295 



The abdomen is much broador bohind than in front, its cuticle 

 is of a very firm texture, and (as well as the cephalo-thorax) 

 it is clothed thinly with rather long, prominent bristles or bristly 

 hairs. 



In distinguishing the male spiders of this gonus (some of 

 which are remarkably similar in general appearanco, colours and 

 markings) the apophysis at the extremity of the radial joints 

 of tho palpi, as woll as tho processes of tho palpal organs, must 

 be carefully examined, since those afford unfailing char- 

 acters for determining the species. This is so, of course, in 

 regard to all spiders, but their help is more necessary here than 

 in some other genera. The palpi are always short ; the 

 digital joint is largo, of a short, broad-oval form pointod at tho 

 extremity. The difference in the relative sizo of tho Boxes is not 

 excessive. 



Tho characteristic abdominal pattern, in both sexes of Xystieus, 

 is a broad dark area on the upper side, occupying almost the 

 whole surface, and taking its form from that of the abdomen, on 

 tho upper side of which there is a longitudinal, strongly dentated, 

 pale band, varying in the greater or less perfection of its outline, 

 and in its breadth, as well as in the presence or absence of spots 

 and other markings on it. The broad area mentioned will be 

 referred to in tho subsequent descriptions as simply the upper side, 

 even though sometimes no more of it is left unoccupied by tho 

 central dentated band than an irregular border. The central 

 band will also be simply referred to as the dentated band. 



The cephalo-thorax also has a distinctive pattern, very similar 

 in all the species of Xysticus, and to which allusion must be 

 made here. A broad, central, longitudinal, pale band runs to, and 

 often through and beyond, tho ocular aroa ; at tho fore end of 

 this band (beginning close behind the eyes) is a dark marking 

 of an angular form, tho point of the angle directed backwards. 

 Sometimes this marking is of a wedge-shape, and sometimes 

 curvi-latoral or spade-shaped; sometimes, when of the latter 

 form, thoro is a wedge-shaped dark marking within its area, 

 and in this caso it is of a paler huo than the rest of tho 



