Gatenby. — Life-history and Habits of Migas distinctus. 235 



hence when the door rises the projection catches the back of it and 

 keeps it at an angle of 60°. On most doors these devices are present to 

 a certain degree, but some doors are without them. It is difficult to 

 say whether or not these above-mentioned devices are made on purpose 

 by the spider. 



The Manner in which the Spider makes her Lid. — The spider begins 

 by weaving a tag-like piece of silk on the hinge side. Having collected 

 fine pieces of earth and stones near by, she gums them one by one to the 

 tag. After she has got a little patch gummed together she turns around 

 in her nest, applies her spinners to the little mosaic, and spins a silken 

 layer under it, which binds it temporarily. She then goes on gumming 

 the pieces together till the door-opening is covered. She then again 

 turns around, and spins another covering over it. In this state the door 

 is flimsy and elastic, and when the spider pulls at it from within (fig. 11) 

 it drops into the mouth of the tube. Some spiders perform their build- 

 ing in a night, others in some days. They generally work at night, 

 although sometimes in daylight. The gum appears to be exuded from 

 the mouth. 



The Tubular Cavity of the Nest. 



The depth and width of the tube varies greatly, depending, of course, 

 upon the size of spider. Generally the nests are from 1 in. to 1^ in. in 

 length, and t 3 q in. to fin. in width, taken lengthwise at the lid. The 

 tube does not remain a uniform width in its entire length, but widens 

 at the terminus to ^ in. (figs. 9, 10, 11, 12, &c.). The reasons for this 

 terminal swelling are two — firstly, to allow room for eggs and young; 

 and, secondly, to allow the spider to move and turn around in the nest. 



Lining of Tube. 



The interior of the tube is lined with a layer of silk, which is thick 

 if the ground is dry or crumbling, thin if it is damp and firm. The 

 rim of the mouth of the nest is generally thicker than the other linings. 



Abnormal Forms of Nests. 



If a bank is very hard or stony the spider is unable to pierce the 

 ground deep enough. In this case man)' kinds of curious nests are seen. 

 The spider generally scrapes out a shallow groove, and makes her silken 

 tube in it. Hence a good deal of the nest is exposed, and to cover it 

 the spider uses an earthy cement-like mixture of mud and stones 

 (fig. 10, c). This is spread over the silk until the projecting unprotected 

 side of the tube closely resembles a rounded stone or piece of earth. The 

 work is marvellously executed, and until the door is discovered it is 

 impossible to detect the artificial side of the tube. The door is discovered 

 on account of the round rim. Sometimes the groove cannot be scraped 

 deep enough, and then the spider makes a small nest like a nut, the door 

 being on one side. This protrudes from the bank, and is covered so as 

 to resemble a stone. 



Another curious form of nest is that with two doors, one at each end 

 of the tube (fig. 13). These two-doored nests are met with in tubes 

 built under stones, on cliffs, and sometimes on trees. Sometimes both 

 doors are large enough for the spider to pass through, but more fre- 

 quently only one door is the proper size, the other one being too small. 

 I believe that when the young spider builds the nest both doors are large 



