22 MELANDER. 



passages ending, in the case under observation, blindly (Fig. 2, r). 

 When the Embiid wishes to turn in its passage it backs partway 

 into a side tunnel until its head is free to point the other way. 

 This is not universal, however. Einbia was several times seen to 

 turn on itself, as its very supple body and unchitinized joints 

 permit it to place the thorax in a line parallel with and touching 

 its abdomen. During the daytime Embia seemed loath to quit 

 its tunnel, and when forced out would always return to it in a 

 few minutes. When in the tunnel it is completely concealed. 

 This accounts for the few specimens, as all were taken when 

 driven from their retreat on the removal of their stone. 



It was stated by Hagen that the web is used in ensnaring 

 prey. Its texture is far too delicate for that purpose, even were 

 its size larger. Embia' s silk is very different from spiders' webs. 

 It is much more frail and of an opalescent whiteness which ren- 

 ders it distinguishable, after practice, from the spider webs com- 

 mon in the same situations. Grassi states : " Evidently the 

 gallery serves to protect the body from too excessive transpira- 

 tion, and to keep about the Einbia an atmosphere not too dry," 

 but it is difficult to see how a net can prevent excessive trans- 

 piration in a dry climate like that of Austin. The tunnels prob- 

 ably serve merely as a retreat. The insect seems entirely con- 

 tented when at home and touching the meshes of its web, so that 

 it may be described as strongly, positively thigmotactic. Indeed, 

 it was frequently observed to stretch its front feet outward, in 

 order to press its back against the soft silk. 



When the web was touched, the Embiid darted out, sometimes 

 head first and sometimes crawfishing. Its backward movements, 

 however, are very different from its normal walk. In moving ahead 

 Embia walks with a sinuous motion, bending its supple body 

 slightly to accommodate the motions of its legs, and covering 

 about two thirds of an inch, or less, in one second. Its recoils are 

 more of a scurry from danger. It then travels a full inch in a 

 second and in a straight path, though it never goes beyond an 

 inch in any single dart. While walking, the abdomen is carried 

 in a very unstaphylinid-like manner, the central part being ele- 

 vated and the tip depressed. Embia was never observed to jump, 

 though the incrassate and muscular femora would at first sight 

 seem to indicate that habit. 



