98 



corresponding occurs in the other, the females, can, it seems to me, 

 never lead to any good or permanent result ')• 



The genus Pachydactijlus Menge, taken up by me (On Eur. 

 Spid. , p. 86) among the synonyms of Walckenaera (Blackw.), does 

 not belong to Erigone (Say. et Aud.), n., but to Euryopis (Menge), Thor. 



(Pag. 197.) E. longipalpis [= Erigone longipalpis (Sund.) 1830]. 



Syn.: 1830. LlNYPHlA LONGIPALPIS Sund., Sv. Spindl. Beskr., in Vet.-Akad. Handl. 



f. 1829, p. 212 ; ibid. , 1832 , p. 259 (ad part. 

 ■ excl. salt. "Var. /?"). 

 P 1833. Erigone atra Blackw., Charact. of some undescr. gen. and spec, of 

 Aran., in Lond. and Edinb. Phil. Mag., 3 Ser. , III, 

 p. 195 (suit, ad part). 

 1841. Argus longbianus Walck., H. N. d. Ins. Apt., II, p. 346 (ad 



partem). 



?1841. „ VAGANS id., ibid., p. 345 (ad partem). 

 1864. Neriene longipalpis Blackw., Spid. of Gr. Brit., IT, p. 274 (ad 



partem). 



1) A complete reelaboration of the numerous European Erigonce is at the 

 present moment one of the chief desiderata of Arachnology. In such a work the 

 determination of species ought to be facilitated by analytical tables , one for the 

 males and one for the females , by sharp diagnoses, and by separately marking 

 and insisting on the peculiarities, whereby each species is especially distinguished 

 from the forms most nearly allied to it. Careful attention must be paid not 

 only to the most conspicuous peculiarities in form, colour, size and in the sexual 

 organs (the male's palpi and the female's vulva), but also to the profile-contour 

 of the cephalothorax, the peculiarities of its surface (depressions and elevations, 

 opacity or brightness, the nature or the absence of puncture or striation and hairy 

 covering), moreover to the form of the face, particularly the height of the cly- 

 peus in comparison with the mandibles and the eye-area, to the relative lengths 

 of the joints composing the palpi, and their form, not only in the <$ but also in 

 the §; to the arrangement, relative size and distances of the eyes, and the di- 

 mensions, form and armature of the mandibles. Equally good characteristics are 

 frequently afforded by the form of the maxillae, the relative length and thickness 

 of the leg-joints, the bristles and hairy covering of the extremities, the nature 

 of the surface of the sternum, the different consistency of the skin on the back 

 of the abdomen, etc. etc. If to these be added microscopical details concerning 

 the organs of copulation, mamilhe, claws etc., so much the better. 



In the examination of specimens preserved in spirits, it is necessary, 

 in order to observe all these particulars, to take up the animal out of the spi- 

 rits and set in on the point of a fine pin, and in doing this some skill is requi- 

 red , to keep the specimen sufficiently dry for observation and at the same time 

 prevent its being destroyed for want of moisture. 



