On EUROPEAN SPIDERS. 73 
Fam. I. THERIDIOIDE. 
Syn.: 1837. Theridides C. Koch, Uebers. d. Arachn.-Syst., 5, p. 6 (ad max. part.). 
1861. Theridiide WestR. (excel. Pholco), Aran. Suec., p. 90. 
1864, 5 Buackw. (excl. Pholco) + Linyphiidee Brackw., Spid. of Gr. Brit., 
IMLS os dns AT) 
1866. Retiariæ (Pachygnathide + Linyphidæ + Therididæ) MENGE, Preuss. Spinn., I, 
p. 94, 100, 146 (ad max part.). 
The European spiders belonging to this family, as well in their ha- 
bits, the construction of their webs and the form they give their cocoons, 
as in their general appearance, exhibit very considerable differences, but 
yet form a perfectly compact and natural group, which it is not easy to 
resolve even into tolerably well-defined sub-families. Nevertheless BLACKWALL 
has divided them into two separate families, Linyphüde and Theridide, 
but without indicating any difference of bodily form between these two fa- 
milies. They are said to be distinguishable however by the different man- 
ner in which the species composing them construct their webs: the Liny- 
phiide fabricate a fine sheet of web, the snares of the Zheridiide on the 
contrary are said to consist of lines intersecting one another in different 
planes and at various angles, and to present the appearance of being con- 
structed without any regular plan '). Even if this basis for their classification 
could be admitted, which seems to me dubious, it not being taken from the 
animals themselves, I still think it does not, if strictly applied, lead to a na- 
tural grouping. Its application would probably in many cases be impossible, 
for the webs of many species belonging to BLACkwALUS Walckenaera and Ne- 
viene are unknown, and it seems to me probable, that these do not all 
construct webs resembling those of Linyphia, nay that some of them fabri- 
cate none at all Steatoda bipunctata and castanea, Lithyphantes corollatus 
and others, belonging to BLACKWALLS Theridion, weave nets not indeed so 
close and fine as those of the Linyphiæ, but which yet have the form of a 
sheet, and are quite as regular as theirs, and these species surely no one 
would think of separating from the Theridiide. Other authors also have 
endeavoured to separate between Theridiidæ and Linyphiide, but it is vain 
to look for any agreement as to which genera are to be assigned to the 
one or other of these groups. SIMON refers Micryphantes to the Linyphide, but 
Erigone to the Theridiide: by BLACKWALL on the other hand the species 
composing both these genera are referred to the Linyphüde. MENGE, who 
1) Conf. Buackw., Spid. of Gr. Britain., II, p. 175 and 210. 
Nova Acta Reg. Soc. Sc. Ups. Ser. III. 10 
