35 



brown colour, without a longitudinal lighter middle, stripe; the belly 

 is in the middle pure black with a bright yellow band or spot on 

 both sides. (Conf. Koch's description, die Arachn. , V, p. 147!). 

 The vulva is of a sufficiently characteristic form to prevent all con- 

 fusion even with Z. atrica and Z. x-notata , whereon more presently. — 

 Of Z. montana C. Koch I have captured some female specimens and 

 an immature male in Switzerland, partly in Berner Oberland and 

 partly at S:t Moritz in Ober-Engaddin. It has been found by C. Koch 

 also only in Alpine tracts ')• v Dr L. Koch has kindly sent me an 

 adult cf and Q from Gallice under the name of Z. alpina L. Koch 2 ), 

 which are somewhat larger than my Swiss specimens. Z. Strmnii 

 again is common in many parts of Sweden, and is also met with 

 in Finnland and Prussia. 



In Z. x-notata the vulva forms a low, transversal, truncated, 

 black or dark-brown elevation or ridge slightly depressed in the 

 middle, which, on the surface turned backwards and towards the 

 belly, shows two small rounded /ove r. In Z. atrica it also exhibits 

 a similar transversal black ridge, but which behind encloses a smal- 

 ler, also transversal, callus of a yellow colour, and divided by a 

 longitudinal impression into two small rounded bumps. This renders 

 it easy to distinguish even by the colour of the vulva between Z. 

 x-notata and Z. atrica: in the former the entire vulva is blackish, 

 in the latter yellow in the middle, behind. 



In Z. montana C. Koch the vulva forms a thick, black, trans- 

 versal protuberance, which, seen from the side, has almost the form 

 of a low, truncated cone, the place of the abscinded apex being occu- 

 pied by a large , rounded fovea open behind and continued backward 

 (and upward) with two short longitudinal impressions , which however 

 are not always visible. 



In Z. Stroemii the vulva runs out into a long (about 3 /* mm > or 

 as long as the tarsus of the 1 st pair), slender, horny, black process 

 pointing backwards; it is slightly curved upward (towards the belly), 

 tapering towards the blunt extremity, flattened beneath, and there 

 provided with a longitudinal furrow. The male's palpus has at the 

 base of the clava, on the exterior side, a strong, curved spur or hook, 



1) When BOckh (Voiiaufige Uebersicht d. wiihrend d. Reise d. Fregatte Novara 

 gesammelten Spinnen, in Verhandlungen d. zool.-botan. Gesellsch. in Wien, XI 

 (1861), p. 390) mentions "Zilla montana Koch" from Madeira, Bio Janeiro and 

 Shanghai, he no doubt confounds this with other related species. 



2) Giebel has already in 1867 (Zur Schweitzer. Spinnenfauna , p. 431) given 

 the name Zdla alpina to another spider. 



