The portions of nests at B and C in [Plate VII.] also belong to Cteniza fodiens, the latter being very similar to A in its surroundings, but having a rather thinner door, slightly hollowed out above (C 1). The smaller nest shown shut at B and open at B 1,[61] is admirably concealed by mosses and lichens, some of which actually grow upon the door, and here two minute trap-doors, belonging to infantine examples of a distinct species of spider (Nemesia meridionalis), are seen on the left hand below.
[61] It must be clearly understood that when the doors are represented as standing open or ajar this is unnatural, as they always close by their own combined weight and elasticity.
It is not rare to find small colonies of nests of the same or distinct species grouped closely together in this way, though I greatly doubt whether one can safely assume their sociability from this fact.
I have very seldom seen nests on the flat ground, where the door would lie horizontally when closed, a sloping or nearly vertical bank being usually chosen, where the door will fall to by its own weight.
In the Ionian Islands another species or variety of Cteniza, described under the name of Cteniza (or Mygale) ionica, and represented as being of an uniform yellow-brown colour, is said to make its nests in the earth of the terraces round the roots of the olive trees.
Mr. Saunders[62] gives admirable figures and descriptions which show us at once that these nests, which he discovered in rather elevated situations in the island of Zante, are of the cork type; but, in this case, the entire door does not shut flush with the surface, as in ordinary cork nests, but has a short spur-like projection above and behind the hinge, serving, as is conjectured, like a lever, by pressing on which from the outside the lid may easily be raised.[63] When I come to speak of the manner of constructing and repairing nests I shall have occasion to refer to these nests again.
[62] Sydney Smith Saunders. Description of a Species of Mygale from Ionia, in Trans. Ent. Soc. London, 1839, vol. iii. p. 160, [Plate IX.]
[63] I must own to some hesitation about accepting this explanation, though I am not prepared to offer any other.
I have not as yet found any nests on the Riviera which can be said to correspond accurately with those of Ct. ionica, the only builders of cork nests yet discovered in this district being Cteniza fodiens and Nemesia cæmentaria.