ON ARACHNIDA. 479 



themselves into the webs abandoned by other araneides, 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 epeirge, and that they even live in houses. It may, never- 

 theless, be possible that they take possession of the webs 

 of other arane'ides, 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 Europams, 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 



