202 Mr. J. Blackwall on new Species of Spiders. 
of their fossils in collections, having given Sir Roderick Murchison 
the erroneous impression that his Upper and Lower Silurian 
groups of fossils (the distinctness of which he himself was the 
first to point out) were mixed together in the Caradoc Sand- 
stone, and that consequently the Bala beds, identical in fossils 
with those of the Caradoc beds (although formerly recognized 
by him as the type of the Cambrian system), could not be sepa- 
rated paleontologically from the Upper Silurian group. The 
Mayhill Sandstone was one of the first formations I recognized, 
on landing near Melbourne, with the usual Upper-Silurian 
fossils; and it is now found here, as in Wales, to be slightly 
unconformable to the Cambrian or Lower Silurian, forming the ~ 
obvious base of the former and totally distinct from the latter. 
XXIII.—WNotes on Spiders, with Descriptions of several Species 
supposed to be new to Arachnologists. By Joun BuacKWALtL, 
F.LS. 
Tribe Octonoculina. 
Family Myearip2. 
Genus Fizistata, Walck. 
Filistata distincta, n. sp. 
Length of the male (not including the falces) =4, of an inch; 
length of the cephalothorax -3,, breadth -3;; breadth of the ab- 
domen 1; length of an anterior leg 11; length of a leg of the 
third pair +3; length of a palpus 43. 
The cephalothorax is oval, clothed with yellowish-grey hairs, 
moderately convex, with a longitudinal indentation in the medial 
line, and an abrupt prominence in the cephalic region, on which 
the eyes are seated, the space between the prominence and the 
frontal margin being sloped forwards; its colour is brownish 
yellow, the medial region being the darkest. The falces are 
small, subconical, prominent, united at the base, somewhat 
hollowed on the inner surface, armed with a very short, curved, 
red-brown fang, and have a pointed tooth near their extremity, 
on the inner side; the maxille, which are strongly curved to- 
wards the lip, have the palpi articulated on the outer side, 
nearer to their extremity than their base; the lip is long, and 
somewhat pointed at its apex; and the sternum is oval and 
hairy. These parts have a brownish-yellow hue, the falces, 
which are rather the darkest-coloured, being tinged with red at 
the extremity. The eyes are closely grouped on the cephalic | 
prominence, and are diaphanous; three on each side, of an oval 
figure, form an irregular triangle, the anterior ones being the 
