Page:Harvesting ants and trap-door spiders. Notes and observations on their habits and dwellings (IA harvestingantstr00mogg).pdf/126



a longitudinal central, and oblique lateral, stripes or bars may be traced on the hinder half; the superior spinners are short and three-jointed, those of the inferior pair are exceedingly minute.

Adult females were found in nests similar to those of Cteniza fodiens.

The cork nests are the simplest form of nest, with the exception of those described above from Jamaica, and have constituted, up to the present time, the only type known in Europe. Their chief claims to our admiration lie in the perfection of workmanship which the doors usually exhibit, and the marvellous concealment which they afford when closed. These doors as a rule fit so tightly [thanks to the accurate adjustment of their sloping sides to the bevelled lip of the tube which receives them,] that they afford a certain amount of mechanical resistance, even when the spider is away. But, after examining a very large series of these cork nests, I find that there is some variation in the degree of perfection attained in their work by different individuals of the same kind. The mechanical resistance is greater or less in proportion to the thickness and weight of the door, and to the slope of its sides, and of the bevelled edges of the tube; and in each of these details a marked difference may be observed.

One might suppose from what has so often been repeated as to the habits of N. cæmentaria, that, whenever any one attempts to open the door, the spider, which is always at home in the day time, would dart up from the bottom of the tube and endeavour to keep it closed by holding on from within.

I cannot say what may take place during the summer months; but from October to May I have but rarely