34 Annah of the South African Museiim. 



According to Mr. Schreiner the nests are built in ruddy, gritty 

 sand, composed of disintegrated dolerite boulders, the particles of 

 which are coarsest on the surface but become finer deeper down. 

 The door consists of a large, four-lobed, flexible flap, shaped like the 

 outspread wings of a butterfly, one pair of lobes or "wings" being 

 slightly wider than the other (pi. I., fig. 5). The beautifully sym- 

 metrical outline is only faintly visible, and is interrupted between 

 the larger pair of lobes, being here continuous with the webbing of 

 the tube. The door of one of the largest nests met with by Mr. 

 Schreiner had an expanse of 40 mm., while that of the nest of a 

 subadult $ sent measured 30 mm. in expanse. 



The door lies in a shallow concave excavation similar in outline, 

 and in the nests figured about 4-5 mm. deep, becoming shallower 

 towards the edges. The inside surface of the excavation is composed 

 of very fine sand of a lighter colour than the surrounding surface, 

 and much smoother. Being larger than the door, it is not com- 

 pletely covered by the latter, a narrow depressed band of the lighter 

 coloured fine sand being left exposed all round (except, of course, 

 at the hinge), and it is only the presence of this band which enables 

 one to detect the nest at all by means of the eye. 



The small entrance to the hole lies just between the bases of the 

 larger lobes. The hole itself descends straight or with a curve to 

 a depth generally less than but never exceeding 2 inches. It is 

 provided on the convex (hinge) side with a small side chamber at 

 some distance from the entrance. According to Mr. Schreiner the 

 hole is generally straight or nearly so, and not so curved as in fig. 7, 

 while the side chamber is generally deeper down. The upper part of 

 the hole is webbed for some distance from the entrance, and is 

 invariably inclined as in fig. 7. At the entrance, which is strongly 

 transversely oval, the upper part of the web-tubing passes over into 

 the door, thus forming a hinge occupying half the circumference of 

 the opening. At the lower half of the opening the web-tubing is 

 produced into a characteristic, rounded, stout, tongue-shaped flap, 

 which lies nearly horizontally on the bottom of the excavation below 

 the centre of the door. 



The structure of the door is peculiar. The door consists merely 

 of a number of particles of fine sand, loosely held together by strands 

 of fine silk. The under side is, however, smooth and well lined with 

 white silk, but the upper surface is strewn with grit and exactly 

 resembles the surrounding ground. The whole forms an extremely 

 flexible mat, which Mr. Schreiner compares with the fresh skin of 

 a kid. Except for the peripheral band it completely fills the ex- 



