( xl ) 



into a ball, and fly o£E with it." The description suggested 

 a Diplopterous rather than a Fossorial wasp. 



In addition to the specimens here tabulated Dr. Bondar's 

 collection exhibited to the meeting contained the tube of a 

 trap-door spider together with the probable owner — a spider 

 of the genus Idiops without label, but placed in close proximity 

 to the tube. To the latter was attached a Portuguese label 

 of which the translation was " Destroyed by wasp. Seems 

 to be a Salius with yellow-tipped antennae, of medium size." 

 The date was Jan. 15, the year being left uncertain. It was 

 probable that the wasp referred to was the Pepsis, taken 

 with a spider of the genus Idiops, Dec. 23, 1914, and standing 

 first in the table on p. xxxvi. This Fossor was of moderate 

 size and had yellow-tipped antennae. It was also probable 

 that the spider had been attacked and stored in its own tube 

 by the Fossor, which was thus saved the trouble of digging 

 a burrow for itself — an example on a larger scale of the tragedy 

 described by W. H. Hudson in " The Naturalist in La Plata " 

 (pp. 180-82 of the 1895 edition) :— 



" On the grassy pampas, dry bare spots of soil are resorted 

 to by a class of spiders that either make or take little holes in 

 the ground to reside in. . . . 



"... Now, in summer, to a dry spot of ground like this, 

 comes a small wasp, scarcely longer than a blue-bottle fly, 

 body and wings of a deep shining purplish blue colour, with 

 only a white mark like a collar on the thorax. ... It visits 

 and explores every crack and hole in the ground, and, if you 

 watch it attentively, you will at length see it, on arriving 

 at a hole, give a little start backwards. It knows that a 

 spider lies concealed within. Presently ... it disappears into 

 the hole and remains there for some time. Then, just when 

 you are beginning to think that the little blue explorer has 

 been trapped, out it rushes, flying in terror, apparently, from 

 the spider who issues close behind in hot pursuit ; but, before 

 they are three inches away from the hole, quick as lightning 

 the wasp turns on its follower, and the two become locked 

 together in a deadly embrace. Looking like one insect, they 

 spin rapidly round for a few moments, then up springs the 

 wasp — victorious. The wretched victim is not dead; its 



