REV. O. P. CAMBRIDGE ON NEW AND RARE BRITISH SPIDERS. 539 
The falces are directed rather backwards; and their extremities extend but very little 
beyond those of the maxillæ. 
The female is rather larger than the male, but resembles it in colours and other 
general characters; the form of the genital aperture is peculiar and best seen from the 
drawing (Pl. XLVI. fig. 9e ); it has no very prominent epigyne connected with it. 
The maville in the female are rather less curved than those of the male. 
Adults of both sexes were sent to me by Mr. James Hardy in October 1871, having 
been then lately found by him on the Cheviot Hills. 
LINYPHIA ? ARCANA, sp. n. (Pl. XLVI. fig. 10.) 
Male adult, length 1% line. 
The whole of the fore part of this spider is yellow, slightly tinged with orange, the 
sternum and tibise of the two foremost pairs of legs being suffused very slightly with 
dusky. 
The abdomen is dull-yellow brown, with some long, pale, oblique lines, forming a kind 
of vandyke pattern on the sides; these are visible in spirit of wine, but probably not 
visible before immersion. 
In form and general structure this species is of the ordinary type. 
The height of the clypeus exceeds one-half that of the facial space. 
The eyes are on black spots, and in the usual position; those of the hinder row are 
equidistant from each other, those of the fore central pair are smallest and contiguous to 
each other, and each is separated from the hind central nearest to it by the same interval 
that separates those of the hind central pair; the foremost row is the shortest and is 
straight, the eyes of each lateral pair being placed obliquely on a slight tubercle. 
The /egs are short, but rather strong; their relative length is 4, 1, 2, 3. They are 
furnished with hairs, bristles, and a few fine spines. This spider is an instance of the 
failure of the criterion furnished as to its genus by the presence or absence of distinct 
spines on the legs; there are undeniably spines on the legs of the two hinder pairs, those 
on the fourth pair being the strongest, while on the legs of the first two pairs they are 
far more slender, and might be described as merely strong bristles. 
The palpi are short and, except the digital joint, not very strong; the cubital joint is 
short, and, besides hairs, has a single, not very long, straight, tapering, black bristle, 
directed forwards from near its fore extremity on the upper side; the radial joint is about 
equal in length to the cubital, but is stronger; it is a little obtusely produced in front, 
and slightly gibbous behind; it is furnished with hairs and short bristles. The digital 
joint is large; it is slightly prominent towards the base near the outer side, at about the 
middle of which there is a slight lobe. 
The palpal organs are highly developed, prominent and complex ; the principal corneous 
process, situated at their base, on the outer side, is of a somewhat concave, crescent- 
form. At the upper, or strongest, portion of the crescent are two small prominences, 
the hinder one being the strongest, the foremost one but slightly prominent beyond the 
margin of the process. 
VOL. XXVIII. 4 D 
