ON EUROPEAN SPIDERS. 9 
kon the priority of these names from TOURNEFORTS 1) Institutiones Rei Herba- 
riae (1719) — the admission of that alternative would cause too great a 
difference between the rules of zoological and botanical nomenclature. As 
for the second alternative, it cannot be thought of for the simple reason, 
that it would certainly be impossible to determine, when and by whom the 
term genera, in the sense in which it is now usually understood, was first 
applied. Now there being in Zoology contemporaneously with TOURNEFORTS 
Institutiones Rei Herbarie no such epoch-constituting work to go out from 
— for it must be admitted that, with respect to nomenclature, that is not 
the case with the famous works of RAY, — it would seem to be the best 
course and that which requires the least change in the existing nomencla- 
ture, to commence, as SUNDEVALL has proposed, reckoning the claims of 
priority for generic names from LiNNÉ's Syst. Nat. Edit. I (1735), the first 
in a systematic respect epoch-constituting zoological work, subsequent to 
the time of RAy and TOURNEFORT, and that in which for the first time real 
genera are arranged and defined consistently throughout the animal king- 
dom. — Some few zoologists indeed remove the limit of priority to a much 
earlier period: WILLOUGHBY, RONDELET, ALDROVANDUS, and even ARISTOTE- 
LES (who did not write in Latin!) have been cited as “authority” after ge- 
neric names, although for several af these authors genera, in the modern 
meaning of the word, had no existence. Moreover it would be a matter of 
no small difficulty for those, who go back to so remote times, to discover 
who first employed such generic names as e. g. Canis, Perca, Musca, 
Aranea! — In Arachnology the manner in which this question may be 
determined is fortunately of no consequence, as all the genera comprehend- 
ed in the classification of Spiders have been formed subsequently to the 
commencement of the present century. 
It follows immediately from the law of priority, that if the same 
name should have been given to two different genera of animals, it belongs 
to the genus jist described under that name; the other genus receives the 
next oldest of the names under which it has been made known, or in the 
absence of such, receives a new name ?. The same rule of course holds 
1) ’TouNEFORTIUS primus characteres genericos ex lege artis condidit": LINN., 
Philos. botan., § 209. 
2) If a genus has been described by two different names, and has resumed (or 
ought to resume) the elder of them, the younger name, or synonym, ought not to 
be considered as free and unappropriated, and should not be employed as name 
of any other new genus than one formed by dividing the genus to which it was 
originally applied. 
Nova Acta Reg. Soc. Sc. Ups. Ser. III. 2 
