22 T. THORELL, 
WESTRING has throughout consistently endeavoured to apply the law 
of the priority of names, and it is therefore only in consequence of his not 
having had access to certain portions of arachnological litterature, that he 
has, instead of the oldest and therefore right names, occasionally used 
newer appellations, not only for a number of species, but even for certain 
genera. But to this we shall have occasion hereafter to return. 
The remarks we have to make against WESTRINGS work are not 
many. It may be mentioned as an imperfection, that the author has paid 
no attention to those characteristics, the examination of which requires the 
aid of the microscope, and some of which, e. g. those derived from the 
structure of the spinners and the claws, are by no means unimportant 
either in classification or specific description. A somewhat more detailed 
account of the different species’ of spiders occurence, economy, industry, ete., 
than what the author has furnished, would have been acceptable, and might 
also certainly by him, who for so long a series of years has devoted his 
attention to that group of animals, easily have been supplied. 
As regards the families into which WESTRING has distributed the 
Swedish spiders, they are, as corresponding with the Latreillean family- 
groups (by me considered as sub-orders) very natural, but might perhaps at 
least in part be resolved with advantage into several, as is particularly 
the case with the Drasside WESTR., which most modern authors divide into 
three or more separate families. With regard to the division of the families 
into genera, the author appears in general to have hit upon the right mean 
course between too strict an adherence to the views of older systematizers and 
the occasionally over minute subdivision of genera, such as has been introdu- 
ced into the territory of arachnology by for instance MENGE; nevertheless it 
appears to us, that some of the older genera preserved unchanged by 
WESTRING, e. g. Theridium, Philodromus, Lycosa, Attus, might well have 
borne with some division, as well as Æpeira, Clubiona, Drassus, ete., which 
he has divided into several smaller generic groups. 
To facilitate comparison between the Spider-fauna of the Scandina- 
vian peninsula and that of Great Britain and Ireland, as they appear in the 
We accordingly find in descriptive works of moderate bulk the diagnoses generally 
so expressed, that they serve to distinguish only those species of the genus, that 
are immediately under treatment, and have therefore no other object than to facili- 
tate the determination of an unknown species. But for that purpose — the only one 
which in a diagnosis needs be considered — it needs not be very verbose, not 
even in very large genera, if nota bene these genera are duly subdivided into smal- 
ler easily distinguishable groups. 
