438 REV. O. P. CAMBRIDGE ON SIBERIAN SPIDERS. [May 6, 



angulipalpis by the form and structure of the sexual aperture, 

 which iu L. karpinskii is more prominent and has a long, 

 strongish, curved epigyne, which arches over from the fore to the 

 hinder part ; this epigyne is of a pale, semidiaphanous, whitish 

 colour, and is dilated in the middle ; in other respects the female 

 resembles the male. 



Both sexes of this Spider in the adult state were contained in the 

 Siberian collection received from M. Taczanowski. 



Linyphia dybowskii, sp. n. (Plate XL. fig. 3.) 



Male adult, length \\ line. 



This interesting Linyphia is closely allied to the foregoing and 

 also to L. angulij)alpis (Westr.), wbich it resembles, both in general 

 form, structure, and colour ; it is, however, larger and deeper- 

 coloured than L. karpinskii, and may be distinguished without 

 difficulty from both species by the structure of the palpi and palpal 

 organs. In L. karpinskii the cubital joint of the palpus is in fact 

 five-sided when looked at in profile, but in the present it is four- 

 sided ; the profile of the upperside, instead of presenting a somewhat 

 angular, as in L. karpinskii, and a strongly angular gibbosity as in 

 L. angulipalpis, consists of an evenly curved or arched line, from the 

 fore extremity of which, where it forms with the lower side a strong 

 prominence, there springs a strong, tapering, black spine, of a strongly 

 curved, and, in fact, of a sickle form, handle and all being repre- 

 sented. The radial joint is very short, much constricted at its 

 junction with the cubital, and a little produced in front. The palpal 

 organs are well developed and complex, consisting of bolder corneous 

 processes than those of L. karpinskii. The figures given of the 

 palpal organs of this species and L. dybowskii, although generally 

 accurate, must not be relied upon for exceeding accuracy of detail ; 

 such minute accuracy, however desirable, could not be obtained 

 under the difficulties under which the figures were drawn. The 

 female of L. dybowskii may be easily distinguished from that of both 

 the other species named by the strikingly different form of the 

 process connected with the sexual aperture. A comparison of the 

 sketches given of that portion of structure of the present species 

 and L. karpinskii will show this at a glance. 



Both sexes of this species, in the adult state, were contained in 

 M. Taczanowski's Siberian collection, made by Dr. Dybowski, 

 whose name I have taken the liberty to confer upon this interesting 

 Spider. 



Linyphia unicornis, sp. n. (Plate XL. fig. 4.) 



Adult male, length 1 line. 



This very distinct and remarkable species has the whole of the 

 fore part (including the legs and palpi, but excepting the sternum) 

 of a clear yellow colour, the sternum being strongly suffused with 

 sooty brown ; the abdomen is of a pale straw-yellow hue, with two 

 longitudinal rows of brown-black blotches ou the upperside, con- 

 verging towards the spinners, and continued in lateral lines or short 



