WALCKENAERA. 
313 
The four intermediate eyes form a trapezoid whose shortest side is before; the other four, 
disposed in pairs on the sides of the anterior part of the cephalo-thorax, are the largest, 
and the two anterior ones of the trapezoid the smallest of the eight. The cephalo-thorax is 
oval, glossy, depressed on the sides, which are marked with slight furrows converging towards 
an indentation in the medial line; the falces are moderately strong, conical, armed with teeth 
on the inner surface, and inclined towards the sternum, which is broad and heart-shaped; the 
maxillm are inclined towards the lip, which is semicircular and prominent at the apex. 
These parts are of a dark-brown colour, the falces and maxillae being the palest. The legs 
are moderately robust, provided with hairs and some erect spines, and have a reddish- 
brown tint; the fourth pair is rather the longest, then the first, which a little surpasses the 
second, and the third pair is the shortest; the two superior tarsal claws are curved and pec¬ 
tinated, and the inferior one is inflected near its base. The palpi resemble the legs in colour. 
The abdomen is oviform, convex above, projecting over the base of the cephalo-thorax; it 
is thinly clothed with hairs, glossy, and of a black hue, that of the branchial opercula being 
dull-yellow. 
The male is rather smaller than the female, but it resembles her in colour and in the 
relative length of its legs. The anterior part of its cephalo-thorax is prominent but obtuse, 
with an oblong indentation on each side, extending backwards from the lateral eyes. The 
cubital and radial joints of the palpi are short; the latter is elongated at its extremity, on the 
inner side, and projects a short, pointed apophysis in front; the digital joint has a dark- 
brown tint; it is very broad and crescent-shaped at the extremity, narrow and prominent at 
the base, convex and hairy externally, concave within, comprising the palpal organs, which 
are highly developed, complicated in structure, with a long, curved, filiform spine, originating 
in a protuberance near the extremity of the inner limb of the crescent, and a straight, pointed 
spine, contiguous to some prominent, transparent membrane, near the extremity of the outer 
limb; these organs are of a dark-brown colour, tinged with red. 
Both sexes of this spider secrete themselves under stones in moist pastures near Llanrwst. 
The male, which has been taken in Berwickshire by Mr. J. Hardy, has the palpal organs 
developed in May. 
Walckenaera picina. PI. XXI, fig. 228. 
Walckenaera picina, Blackw., Linn. Trans., vol. xviii, p. 640. 
_ _ Blackw., Annals and Mag. of Nat. Hist., second series, vol. ix, 
p. 466. 
Argus picinus, Walck., Hist. Nat. des Insect. Apt., tom. iv, p. 50/. 
Length of the male, T ’,th of an inch ; length of the cephalo-thorax, 55 th, breadth, 3 ' 5 nd; 
breadth of the abdomen, ^th; length of a posterior leg, ^th; length of a leg of the third 
pair, ^th. 
The cephalo-thorax has a small indentation in the medial line ; the anterior part is promi- 
