Mr. BuackwaLv's Descriptions of new Species of Spiders. 635 
21. Watckenaéra bicolor. Maris cephalo-thorace mandibulis maxillis labio 
sterno pedibus palpisque brunneis; abdomine nigricante; cephalo-thoracis 
parte anteriori prominente obtusa utrinque indentata. 
Length of the male yth of an inch; length of cephalo-thorax ; breadth 3; ; 
- breadth of abdomen 35; length of an anterior leg r; length of a leg of 
the third pair Pg. 
Cephalo-thorax oval, convex above, glossy, prominent, but obtuse, in front, 
with a slight indentation in the medial line of the posterior region, and 
another immediately behind each lateral pair of eyes. Mandibles conical, 
armed with teeth on the inner surface, and inclined towards the sternum, 
which is broad and heart-shaped. These parts, with the maxillæ, lip, 
legs, and palpi, are brown, the lip being the darkest, and the legs the 
lightest coloured. First and fourth pairs of legs, which are the longest, 
equal in length, third pair the shortest. Third and fourth joints of the 
palpi short, the latter being much the stronger ; fifth joint somewhat oval, 
having a projection on the outer side; it is convex and hairy externally, 
concave witbin, comprising the palpal organs, which are highly developed, 
complicated in structure, with a slender, corneous process at the superior 
part, directed upwards, a bold prominence on the inner side, and a fine, 
convoluted, filiform spine, enveloped in a delicate membrane, extending 
from the upper part of the extremity; their colour is red-brown. Abdo- 
men oviform, thinly covered with hairs, convex above, projecting over the 
base of the cephalo-thorax ; it is of a brownish black colour. Plates of 
the spiracles pale yellow. 
Males of this species, with the palpal organs fully developed, were taken in 
July 1836, on rails near Llanrwst. 
22. Walckenaéra parva. Brunnea, abdomine Saturatiore ; maris cephalo-tho- 
race anticè parüm prominente utrinque indentato. 
Length of the female j';th of an inch; length of cephalo-thorax 3s ; breadth 
dg; breadth of abdomen 45; length of an anterior leg Ir; length ofa 
leg of the third pair 20. i 
Cephalo-thorax oval, glossy, very convex behind the eyes, depressed in the 
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