304 
LINYPHIIDvE. 
and the legs the lightest coloured. The two superior tarsal claws are curved and pectinated, 
and the inferior one is inflected near its base. The cubital and radial joints of the palpi are 
short, the latter being much the stronger; the digital joint is oval, with a projection on the 
outer side; it is convex and hairy externally, concave within, comprising the palpal organs, 
which are highly developed, complicated in structure, with a slender process at the base, 
directed upwards, a bold protuberance on the inner side, and a fine, convoluted, filiform spine, 
enveloped in membrane, extending from the upper part to the extremity ; their colour is red- 
brown. The abdomen is oviform, thinly clothed with hairs, convex above, projecting over 
the base of the cephalo-thorax; it is of a brownish-black colour, and that of the branchial 
opercula is pale-yellow. 
M. Walckenaer is of opinion that Walclcenaera bicolor should rank as a synonym of Argus 
elongatus (Hist. Nat. des Insect. Apt., t. iv, p. 509); but they may be readily distinguished 
from each other by differences in size, structure, and colour. 
Males of this species, with the palpal organs fully developed, were taken in July, 1836, 
on rails near Llanrwst. 
Walckenaera parva. PI. XXI, fig. 219. 
Walckenaera parva, Blackw. Linn. Trans., vol. xviii, p. 635. 
— — Blackw., Annals and Mag. of Nat. Hist., second series, vol. ix, 
p. 465. 
Argus parvus, Walck., Hist. Nat. des Insect. Apt., tom. iv, p. 508. 
Length of the female, -,’ B th of an inch; length of the cephalo-thorax, 5 (nd, breadth, ^th; 
breadth of the abdomen, ^th ; length of an anterior leg, T ' 3 th; length of a leg of the third 
pair, 5 ' s th. 
The cephalo-thorax is oval, glossy, very convex behind the eyes, depressed in the 
posterior region, with an exceedingly minute indentation in the medial line; the falces are 
moderately powerful, conical, armed with teeth on the inner surface, and inclined towards the 
sternum, which is heart-shaped and glossy; the maxillae are strong, and inclined towards the 
lip, which is semicircular and prominent at the apex. These parts, with the legs and palpi, 
are of a brown colour, the falces, lip, and margins of the cephalo-thorax being the darkest. 
The two superior tarsal claws are curved and pectinated, and the inferior one is inflected near 
its base. The abdomen is oviform, convex above, projecting over the base of the cephalo- 
thorax ; it is thinly clothed with hairs, glossy, and of a very dark, brown-black hue, that of 
the branchial opercula being brown. 
The male, though smaller than the female, resembles her in colour; but it differs from 
her in having an indentation on each side of the anterior part of the cephalo-thorax, imme¬ 
diately behind the lateral eyes. The radial joint of the palpi, which is rather shorter and 
stronger than the cubital, projects an acute, prominent apophysis from its extremity, in front; 
the digital joint is oval, convex and hairy externally,concave within, comprising the palpal organs, 
