I9IO. Jackson — Rare hish Spiders obtained in \<:)0(^. 143 



vulvae eveo'thing depends on the exact position of the 

 specimen. A very slight tilting either one way or the other 

 jDroduces what appear to be wonderful specific differences. 

 Again, in the same species, there is a wide range of variation, 

 and even amongst specimens taken in the same locality it is 

 sometimes difiicult to find two exactly alike. The same 

 remarks apply to the other species of the genus, and I do not 

 think a good case has yet been made out for the female of the 

 much commoner E. promiscua^ Camb. 



In E. arciica, White, the posterior border of the epigyne is 

 nearly always rather deeply embayed by a median flexure. 

 This is usually vestigial or absent in E. lofigipalpis, Sund. 



The vulvae of E. atra, BL, and E. de?itipalpis, Wid., have 

 been figured at least three times ^, -, •\ and I think correctly, 

 only it must be remembered that in each case extreme speci- 

 mens have been selected. In some cases, I think, it is im- 

 possible to be certain of the species, even when the vulvae are 

 very carefully examined. 



Turning to the males, a much more satisfactory state of 

 things is seen, all the species being recognizable by means of 

 a careful examination of the palpi. The structure of the 

 tibiae of those limbs divides the six species into two groups. 



In the first, which includes E. de7Uipaipis, Wid., and E. 

 promisaia, Camb., the tibia, viewed from the outer side, shows 

 three processes or apophyses, a superior, an external or inter- 

 mediate (viewed in profile), and an inferior. The superior 

 process is expanded in the horizontal direction, and forms a 

 more or less broad plate on the dorsum of the article, whilst 

 the intermediate one is placed almost on the same level and 

 just on its outer aspect. The inferior process is much more 

 removed from the intermediate one than the latter is from its 

 superior fellow, and is always provided with a strong tooth 

 on its inferior surface. 



In the second group the superior process is not expanded ; 

 the intermediate process is much separated from it, the dis* 

 tance between the two being not very different from the 

 distance between the intermediate and inferior processes. 



^Chyzer and Kulczynski, " Araneae Hungariae," vol. ii., plate iii., figs 



38,39- 

 ^Bosenberg, '* Die Spiuueu Deutschlauds," plate xv., figs. 237, 238. 



^Pickard-Cambridge, " On New and Rare British Arachnida." Proc, 



Dorset Field Club^ 1905, plate B, figs. 3-8. 



