624 Mr. Back walls Descriptions of new Species of Spiders. 
rows, whose convexity is directed backwards; the lateral eyes are the 
largest, and the intermediate ones of the anterior row the smallest of the 
eight. Abdomen soot-coloured, thickly covered with hairs, short, rather 
larger at the posterior than the anterior extremity, convex above, pro- 
jecting a little over the base of the cephalo-thorax. Spinners brown; the 
superior pair, which is much longer than the rest, and triarticulate, has 
the spinning-tubes arranged along the inferior surface of the terminal 
joint. Sexual organs prominent, and dark reddish brown. Plates of the 
spiracles pale yellow. 
About midsummer, individuals of this species may be seen on rails and 
gates in pastures near Llanrwst in considerable numbers, but they are all 
females. The only male which has come under my observation was found 
beneath a stone imbedded in earth, in the autumn of 1837. It bore a close 
. resemblance to the other sex, but escaped from me before I had an opportu- 
nity of describing the structure of the palpal organs, which were completely 
developed. 
12. Agelena celans. Cephalo-thorace saturatè brunneo lateribus fasciaque 
medianá flavescenti-brunneis ; oculis seriei anterioris intermediis omnium 
multó minimis; mandibulis maxillis labio pedibus palpisque rufo-brun- 
neis ; abdomine saturaté brunneo rufescenti et flavescenti tincto, fascia 
mediana obscura dentatà rufescenti-brunneá. P 
Length of the female 3th of an inch; length of cephalo-thorax 15 breadth — 
. Ye; breadth of abdomen nr; length of a posterior leg 16; length ofa 
leg of the third pair 3%. P 
Anterior part of the cephalo-thorax slightly compressed; sides depressed, 
marked with furrows diverging from the upper part to the margins; in 
the medial line of the posterior region there is a narrow indentation; it 
is hairy, and of a very dark brown colour, with yellowish brown lateral 
margins, and a band of the same hue extending along the middle. Eyes 
disposed on the fore-part of the cephalo-thorax in two transverse, cone 
nearly parallel rows, whose convexity is directed backwards; the lateral 
eyes are the largest, and the intermediate ones of the anterior row much 
