188P.] REV. O. p. CAMBRIDGE ON NEW ARANEIDEA, 37 



Genus Idiops, Perty. 

 Idiops colletti, sp. n. (Plate II. fig. 2.) 



Adult female. Length 1()| lines ; length of cephalothorax 4f 

 lines ; breadth of cephalothorax, at widest part, 3|. 



Cephalothorax longer than broad, the fore and hinder extremities 

 equal in breadth ; thoracic indentation large, deep, curved, the con- 

 vexity of the curve directed backwards ; the occiput is very convex. 

 The colour of the cephalothorax is pale yellow-brown, clothed with 

 a few hairs, and two longish, erect, tapering bristles placed trans- 

 versely just in front of the occipital convexity. 



The eyes 6i the anterior pair are close to the fore margin of the 

 cephalothorax, rather laro;e, and largest of the eight, oval, placed 

 obliquely and separated from each other by less than half the longest 

 diameter ; from between these two eyes spring one or two longish 

 prominent black bristles. The four central eyes of the posterior 

 group, which is separated from the anterior pair by nearly about 

 double its longitudinal diameter, form a square, the foremost eyes 

 being smallest ; those of the posterior row, which are of about equal 

 size, form a moderately curved transverse line whose convexity is 

 directed backwards. The interval between the two central eyes of 

 this row is distinctly greater than that which separates each from the 

 lateral eye next to it ; tliis latter interval is as nearly as possible 

 equal to an eye's diameter. The ocular area forms (roughly) an 

 equilateral triangle. 



The legs are short, stout, 4, 1 , 2, 3 ; those of the third and fourth 

 pairs considerably stoutest, furnished with hairs and spines ; the 

 latter are of different lengths and strength, many being small and of 

 a denticulate nature, and are chiefly on each side of the tibiae, meta- 

 tarsi, and tarsi of the two anterior pairs ; those on the third pair are 

 chiefly on the upperside of the genuae, tibiae, metatarsi, and tarsi, 

 while on the fourth pair the spines are few and those mostly be- 

 neath the metatarsi and tarsi. 



The palpi are similar in colour to the legs, and armed as those of 

 the first and second pairs. 



The /a/ce« are moderate in length and strength, of a darker hue 

 than the cephalothorax, and armed with numerous strong short 

 spines near the inner side of their fore extremity. 



Maxillce cylindrical and thickly covered on their anterior sides 

 with small denticulations or spines. 



Labium somewhat quadrangular, broad at the base (broader than 

 long), narrower at the apex, where there are a few small spinous 

 denticulations, chiefly in a transverse row close to the margin. 



Sternum broadest behind, and longer than broad, incurved at its 

 fore extremity, similar in colour to the cephalothorax. 



Abdomen dull clay- colour, thinly clothed with fine hairs of different 

 lengths. Spinners 4, those of the superior pair short, 3-jointed, but 

 very strong ; the inferior pair very small and close beneath the base 

 of the upper ones. 



Two adult females of this spider were received from General 



