Page:Supplement to harvesting ants and trap-door spiders (IA supplementtoharv00mogg).pdf/168

 joints of the palpi, have strong lateral brush-like fringes of close-set sooty black hairs. The superior pair of tarsal claws are denticulated, but not uniformly either in strength, number, or position.

No doubt this will prove a very troublesome spider to distinguish with certainty from N. cæmentaria, but the almost constant presence of a spine or spines on the outer face of the genual joint of the third pair of legs seems to be a good distinguishing character; in no one example out of nine carefully examined could I detect their absence altogether, while a single spine even on N. cæmentaria is rare.

In the present species five examples had three spines on each of these joints; two had two spines on each; one had a single spine on each; another had one on one side, two on the other.

The nest, however, is very characteristic and peculiar. It is of the wafer-lid type, and so cannot, from even the outside, be mistaken for that of N. cæmentaria, which is of the cork-lid type; it is, moreover, branched below, while that of N. cæmentaria is a single unbranched tube. It has also an inside door, or valve, of very remarkable construction, having two perfect cork-like faces, securely shutting off either the branch, or the main tube just above the branch, at pleasure. By this latter character it is distinguished also from the tube of N. Manderstjernæ, as well as by the absence of a second short branch or cavity, lately discovered in the nest of this last spider. Examples of this spider were found, not unfrequently, but invariably in such nests as that above described, at Hyères.

The female sex only has yet been met with.

Habitat. Hyères.