378 REV. O. P. CAMBRIDGE ON NEW DRASS1DES. [Julie 2, 



digital joint is of ordinary form, rather large, and longer than the 

 radial and cubital joints together. The palpal organs are well deve- 

 loped, but not very complex, consisting of several corneous lobes and 

 processes of different forms. 



The falces are of moderate length and strength, a little projecting, 

 and rather prominent near their base in front, where there are nume- 

 rous long, coarse, prominent bristles. 



Tbe maxilla are moderately long ; they are broad and strong at 

 and below the insertion of the palpi, which spring from a little more 

 than halfway towards their extremities ; they are curved towards 

 the labium, and broadly impressed across the middle of their front 

 surface, and are rounded on the outer side and obliquely truncated on 

 the inner side at their extremities. 



The labium is of an oblong-oval form, truncated at the apex ; the 

 margins are impressed and somewhat constricted, giving to it, as well 

 as to the same portion of structure in many other species of this 

 genus, a peculiar appearance. 



Tbe stsrnum, together with the labium and maxillce, are of a yel- 

 low-brown colour. 



The abdomen is of ordinary size, and narrow oblong-oval form, 

 well clothed with hairs, and of a sooty black colour ; on the fore part 

 of the upperside is a dull, obscure, yellowish- brown, elongate patch, 

 followed by the ordinary six linear spots in two longitudinal opposed 

 curved lines ; these are, however, very indistinct ; the underside is 

 dull brownish, tinged with yellow. The spinners of the inferior pair 

 are greatly the longest and strongest ; the rest are very much smaller, 

 especially those of the central pair, which are almost imperceptible. 



This Spider is very nearly allied to Prosthesima (Melanophora) 

 Iceta (Cambr.), found in Palestine and also in Egypt; but Dr. 

 L. Koch's opinion agrees with my own, that it is quite distinct. 

 There is a slight difference in the structure of the palpal organs ; 

 the falces are less prominent at their base in front ; and the spinners 

 of the superior pair are, in P. tristicula, shorter than in P. Iceta. 



The generic distinction between Prosthesima and Drassus is slight, 

 consisting chiefly in the position of the palpi with respect to the max- 

 illae : in Drassus the palpi arise from the maxillae at or below the 

 middle, never above it ; in Prosthesima they issue at or above the 

 middle, i. e. nearer to the extremities, but never below it. The 

 maxillae also are more strongly impressed or constricted transversely 

 in front near the middle. 



An adult male of P. tristicula was found by myself under a piece 

 of rock near Alexandria, in April 1864. 



Prosthesima lugubris, sp. n. (Plate LI. fig. 7.) 



Adult female, length 3 lines. 



This Spider is of ordinary form and general structure. 



The cephalothorux is deep black-brown, its highest point in the 

 profile-line being at the beginning of the hind slope. The legs, palpi, 

 falces, and other fore parts, except the sternum, are deep brown, the 

 tarsi being reddish yellow-brown, and the abdomen black. 



