ON ARACHNIDA. 
479 
themselves into the webs abandoned by other aranei'des, and 
profit by the fruits of their labours. We speak here only of 
species indigenous to Europe. It would seem, according to 
the observations of some travellers, that the other exotic 
thomisi are more industrious, and approach in that respect to 
the epeirae, and that they even live in houses. It may, never- 
theless, be possible that they take possession of the webs 
of other aranei’des, as M. Walckenaer observes concerning the 
thomisi of Europe. The latter are sometimes embarrassed 
in the threads of the epeirse, and serve them for food, as 
Lister has observed. 
Degeer has witnessed the coupling of the Thomisus citreus . 
Having found, in the month of May, many individuals on a 
willow bough, he put them into the same sand-box ; the 
weakest soon became the prey of the strongest, and he was 
obliged to separate them. He discovered among them an 
individual differently coloured, which he imagined to belong 
to another species. But he soon was perfectly convinced 
that it was a male, by seeing it couple. There is nothing 
different from the other genera in this particular. 
The cocoon is composed of a white silk, very close, and 
forming a papyraceous or membranous tissue. It is usually 
orbicular or very flatted. We shall have an idea of its form, by 
imagining two caps a little gibbous, applied one against the 
other in an opposite direction, and united at their edges. 
Lister describes that of one species, which is snow-white, 
angular, and of a radiated form. It was found attached to a 
little branch of the ulex Europmus , at the commencement of 
June. He saw, on the same shrub, at the same period, the 
cocoon of another species of the same genus, and which was 
attached to one of the summits of the branches; the female 
was clinging to the cocoon. Lister having detached the 
branch which bore it, and having placed it along with the 
spider in a box, this tender mother did not attempt to ascend 
