Mr. Blackwall on undescribed Species of Araneidze. 487 
region. Mandibles powerful, conical, vertical, convex in front, and armed 
with teeth on the inner surface. Maxille enlarged at the base, where the 
palpi are inserted, and inclined towards the lip, which is semicircular and 
prominent at the apex. Pectus heart-shaped. These parts are dark brown, 
with a slight tinge of red, the pectus, lip, and anterior part of the cepha- 
lothorax being the darkest. Legs and palpi robust, and of a red colour. 
Each tarsus is terminated by three claws; the two superior ones are pec- 
tinated about half their length from the base, and the inferior one is in- 
flected near its insertion. The third and fourth joints of the palpi are 
short, the former, which is considerably the stronger, being convex in front ; 
the latter projects two apophyses from its anterior extremity ; ene before, 
which terminates in a corneous point, and has a small, acute, corneous 
prominence on the inner side; the other underneath, which is provided 
with a corneous point on the outer side: the fifth joint is oval, convex and 
hairy externally, concave within, comprising the palpal organs; they are 
highly developed, complicated in structure, with a corneous process at the 
upper part curved outwards, and are of a dark red-brown colour. Ab- 
domen oval, convex above, projecting over the base of the cephalothorax ; 
it is thinly covered with hair, glossy, and of a brownish-black colour. 
Plates of the spiracles pale yellowish-white. 
Length, from the anterior part of the cephalothorax to the extremity of 
the abdomen 3th of an inch; length of the cephalothorax ;-; breadth 3, ; 
breadth of the abdomen -~, ; length of an anterior leg +; length of a leg 
of the third pair +. 
I found one male only of this species, under a fragment of rock in a 
wood at Oakland, in June 1835. 
Tribe, ORBITELE, i 
Genus, Linyphia, \ Latreille. 
Linyphia nigella. 
Cephaiothorax oval, convex, glossy, with an indentation in the medial 
line of the posterior region; it is of a dark brown colour approaching to 
black. Mandibles long, powerful, armed with teeth on the inner surface, 
divergent at the extremities, of a deep brown colour tinged with red, and 
inclined towards the pectus, which is heart-shaped, and of a brownish black 
hue. Maxille strong, longer than broad, with the exterior angle, at the 
extremity, curvilinear; they resemble the mandibles in colour, and incline 
a little towards the lip, which is semicircular, prominent at the apex, and 
brownish black. Legs long and slender, provided with hairs and a few 
spines; their colour is pale yellowish brown, the thighs having a tinge of 
red. Each tarsus is terminated by three claws; the two superior Ones are 
curved and pectinated, and the inferior one is inflected near its base. 
Eyes disposed in two transverse rows on the anterior part of the cephalo- 
thorax ; the intermediate eyes of both rows form a trapezoid, whose an- 
terior side is considerably the shortest, and the lateral ones are placed 
obliquely in pairs, each pair being seated on a small eminence, and gemi- 
nated ; the posterior eyes of the trapezoid are the largest, and the anterior 
ones much the smallest of the eight. The third and fourth joints of the 
palpi are short, the latter, which is much the stronger, being prominent on 
the inner side, at the lower extremity: the fifth joint is of an irrregular 
oval figure, convex and hairy externally, concave within, comprising the 
palpal organs, which are highly developed, complicated in structure, having 
a small projection at the upper part, in front, and a large corneous spine, 
originating in the upper part of the under side, extending to the termina- 
tion of the joint, where it is curved into a circular form, the extremity 
projecting a little; the colour of these organs is dark reddish brown, 
