94 TRAP-DOOR SPIDERS. 



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 conceal- 

 ment 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 the}^ 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 thick- 

 ness 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 difierence may be 

 observed. 



One might suppose from what has so often been 

 repeated as to the habits ofiV. cceiiieniaria,i):i2ki, when- 

 ever 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 



