156 REV. O. P. CAMBRIDGE ON THE GENUS IDIOPS. [Mar. 10, 
The spinners were hidden beneath the dense hairy covering of 
that portion of the abdomen. 
This fine and distinct species is described from a specimen in the 
British-Museum collection, received from the Swan River, Australia. 
In its general form and character it mostly resembles Idiops kochu 
(a native of South America); but it may readily be distinguished 
from all yet known species of the genus by the striking contrast of 
its colours. The specific name conferred upon it needs no explana- 
tion to those who are aware of Mr. John Blackwall’s long and 
unwearied labours in the field of araneological science. 
Ipiors THORELLII, n. sp. (Plate VIII. fig. 6.) 
Male adult: length 44 lines; length of cephalothorax 23 lines, 
breadth of cephalothorax 2 lines. 
The fore part (including the legs and palpi) of this Spider is of an 
orange-yellow-brown colour; it is very sparingly furnished with 
hairs, and the legs have a few fine spines. The abdomen is dark 
yellow-brown ; the form of the cephalothorax is a broad but regular 
oval, depressed above; the normal furrows and indentations are 
fairly marked. The eyes are seated in the normal position upon two 
tubercular elevations, as in Idiops meadii; the two which form 
the first row are the largest of the eight, and very near together ; 
they are situated close above the frontal margin, and form, with 
those of the second row, a narrow oblong figure, whose hinder width 
is the greatest ; the two intermediate eyes of the hinder row are the 
smallest of the eight, and much further from each other than each 
is from the end one on its side. The falces are moderate in length 
and strength, and are armed with a group of strongish spines near 
their extremities on the upperside. The palpi are long and strong: 
the radial joint is very strong, longer than the cubital, and tumid 
behind ; it has a prominence on the middle of the outer side, armed 
with small tooth-like spines ; near the outer extremity of this joint 
is another prominence, smaller, but similarly armed: the palpal 
organs consist of a large, globular, corneous lobe, prolonged into 
a not very large, nor very long-pointed, curved, beak-like projec- 
tion: the form of the maxillze and labium is normal ; but the sternum 
is of a somewhat pentagonal form, moderate in size, and broader 
behind than before. The /egs are moderate in length and strength ; 
their relative length is 4, 1, 2, 3; the tibie of the first pair 
have two corneous projections near their extremities on the inner 
side; and each tarsus terminates with three claws, of which the 
two superior ones are pectinated, and the inferior one much the 
smallest. 
A single example of this species is in the British-Museum col- 
lection. 
Hab. South Africa. Its small size, as well as its colours and 
structure, will readily distinguish it from others of the genus. The 
specific name given to it is that of Dr. T. Thorell, Adj. Prof. Zool. 
Univ. Upsale, and a distinguished araneologist. 
