488 Mr. Blackwall on undescribed Species of Araneide. 
The convex sides of the fifth or terminal jvints of the palpi are directed 
towards each other. Abdomen oval, convex above, projecting over the 
base of the cephalothorax; it is thinly covered with hair, glossy, and 
brownish black. Plates of the spiracles pale yellowish brown. Some in- 
dividuals have a series of obscure, angular lines of a yellowish brown co- 
lour, whose vertices are directed forwards, extending along the middle of 
the upper part. 
. Length, from the anterior part of the cephalothorax to the extremity of 
the abdomen, 4th of an inch; length of the cephalothorax +; ; breadth 
2,3 breadth of theabdomen ~,; length of an anterior leg +4; length of 
a leg of the third pair 3. 
Specimens of this species were procured under fragments of rock in the 
woods at Oakland, in September 1835, but they were all males. 
Linyphia tardipes. 
The cephalothorax of this interesting species is oval, convex, glossy, de- 
pressed and somewhat rounded before, with an indentation in the medial 
line of the posterior region; its colour is reddish brown, with a broad band 
of blackish brown extending along each side. Mandibles powerful, conical, 
divergent at the extremities, and inclined towards the pectus; they are 
terminated by a long nail slightly curved at its extremity, and are armed 
with two rows of teeth cn the inner surface, the anterior row being re- 
markably long and fine. Maxille strong, straight, and somewhat quadrate, 
having the exterior angle, at their extremity, curvilinear. Lip semicircular 
and prominent at the apex. The pectus, which is heart-shaped, is finely 
pointed at its posterior extremity. These parts are of a reddish brown 
colour, the pectus and lip being rather the darkest. Eyes placed on black 
spots on the anterior part of the cephalothorax; four are intermediate 
and form a square nearly, the two in front being the largest of the eight ; 
the other four are disposed in pairs on the sides of the square; the eyes 
constituting each pair are placed obliquely on a small eminence, and are 
contiguous. The palpi are furnished with spines, and have a slightly 
curved, slender claw at their extremity; their colour is reddish brown. 
Legs moderately robust, supplied with hairs and a few fine, erect spines ; 
they are of a reddish brown colour obscurely banded with brownish black ; 
the first pair is the longest, the second and fourth pairs are nearly equal 
in length, and the third pair is the shortest. Each tarsus is terminated by 
three claws ; the two superior ones are curved, and the inferior one is in- 
flected near its base. Abdomen oval, convex above, rather broader at the 
posterior than the anterior extremity, and projects over the base of the 
cephalcthorax ; it is thinly covered with hair, glossy, and of a reddish 
brown colour on the upper side with a few minute, whitish spots inter- 
spersed, and a series of large, brownish black blotches extending along each 
side of the medial line ; these blotches unite, as they approach the spinners, 
and form transverse, curved bands; the sides are brownish black, minutely 
mottled with reddish brown; the under side is dark brown, or brownish 
black. Plates of the spiracles pale yellow. Connected with the sexual organs 
is a large and very prominent, curved process of a dark red-brown colour ; 
it is abruptly contracted in the curvature, and is recurved at the extremity, 
which is enlarged and deeply notched. 
Length, from the anterior part of the cephalothorax to the extremity of 
the abdomen, 4th of an inch ; length of the cephalothorax ,; breadth 7, ; 
breadth of the abdomen +';; length of an anterior leg ,4, ; length of a leg 
of the third pair 4. 
The male resembles the female in colour, and in the relative length of 
the legs, but their absolute length is greater, an anterior one measuring 
