On EUROPEAN SPIDERS. 3 
to intimacy with the distinguishing features of most of the species described 
by both the older and younger Swedish arachnologists, and which are taken 
up in the followmg work. 
As regards non-Swedish species, I cannot, it is true, lay claim to 
the same degree of certainty. By means of the collections of Arachnoidea, 
which I have formed during several journeys and visits of considerable length 
to different countries of Europe, (as e. g. many parts of Germany, Switzer- 
land, France and Italy), as well as through presents of various European 
spiders and other valuable communications from several Zoologists (among 
whom I may with thankfulness mention the late Prof. AL. v. NORDMANN, Dr L. 
Kocx, Count E. KEYSERLING, Dr E. ÖHLERT and Director L. REDTENBACHER), 
Ihave however aequired a tolerably good view of the European spider-fauna 
and have arrived at certainty in several complicated questions of synonymity. 
My remarks upon non-Swedish species are however confined to such forms 
as are either generally known or easily determinable, and I have moreover, 
both a regards Swedish and other spiders, specially noted, by placing an 
asterisk before the name, all the cases, in which I have not learned by 
actual inspection to know the species or genus I treat of. 
The rules, which I consider ought to be observed in deciding con- 
troverted questions of zoological nomenclature, and which I have alluded to 
and endeavoured to apply in my Recensio critica Aran., are generally in ac- 
cordance with those laid down in Annals and Magazine of Natural History, 
Ser. 1, Vol xr, p. 259 et seq. under the title: Series of Propositions for 
rendering the Nomenclature of Zoology uniform and permanent, being the Re- 
port of a Committee for the consideration of the subject appointed by the Bri- 
tisk Association for the Advancement of Science.) These propositions are for 
the most part merely a repetition or development of the principles already 
laid down by LINNÉ iu his Philosophia Botanica, amd which FABRICIUS af- 
terwards in his Philosophia Entomologica applied to Entomological Nomen- 
clature. Since however my views differ on a few points from those of the 
British Committee, and since moreover its above cited work is far less ge- 
nerally known than it deserves to be, I think it best here to give a brief 
account of the rules I have in the following pages applied. 
Suecicarum, quas descripserunt CLERCKIUS, LiNNæus, DE GEERUS (in Acta Reg. So- 
cietatis Scientiarum Upsal. 1856; and "Om Clercks Original-Spindel-samling” [On 
Clerck’sOriginal Collection of Spiders] (in Ofvers. af K. Vet. Akad. Fórhandl. 1858). 
2) Compare also O. A. L. Mörcn, Observations on Conchological Nomenclature, 
ibid. 3 Ser., Vol. II, p. 133; Asa Gray, On Scientific Nomenclature, ibid. 3 Ser. 
Vol. XIII, p. 517. 
