586 Insects. 



of the thimble- cell. The next load was laid on the ridge, but so as 

 to be higher at the apex than at any other part, and made slightly con- 

 cave ; when the tip was made, the work proceeded regularly by addi- 

 tions to the edges, which were smoothly laid on, and always in the 

 same slanting direction that had been given at first by raising one end 

 of the incipient oval; so that an unfinished cell in any stage of pro- 

 gress appears like a cylinder cut off by a diagonal section. This is 

 not casual, but invariable, as the ridges remaining plainly mark the 

 precise limits of every separate load. When a little more in length is 

 finished than suffices for a single cell, the work ceases awhile, an egg 

 is laid in the bottom (though this end is generally uppermost) and spi- 

 ders are brought in. This species usually, not always, selects a very 

 beautiful species of Tetragnatha, bright green with white spots ; and 

 it is worth remarking, that spiders are carried both with the jaws and 

 feet ; one of the fore legs of the spider being grasped in the mouth, 

 while its body is held under the body of the fly, and sustained by the 

 anterior and middle legs and feet, the posterior pair being extended 

 behind as usual during flight. I have given a figure of this species 

 with a spider, and with its nest, which was carefully copied from the 

 life, in my ' Introduction to Zoology,' ii. 347. When the first cell is 

 stocked, it is closed up by a transverse partition of mud, and the thim- 

 ble goes on increasing in length as before ; when finished, one will 

 contain three or even four cells ; and then a new one is commenced 

 adjoining and parallel with it. In both this and the other species, I 

 believe the inclosed grub eats only the abdomens of the spiders (which 

 are so stung as to be helpless but not dead), as the cephalo-thorax 

 and legs of each generally may be found afterwards in the cell. 



With the name of this latter species I am not acquainted, nor can 

 I find it in the national collection, common as it is in the States. It 

 differs from the former, and perhaps from Pelopaeus generally, in hav- 

 ing the abdomen not obviously peduncled, but gradually thickening, 

 club-like, to the hinder part : that segment which Mr. Newman has 

 called the podeon,* is furnished with a curious hooked spur on its 

 ventral surface, pointing backwards, by which the species may very 

 readily be distinguished. The colour is black, highly polished. 



P. H. Gosse. 

 Kentish Town, May 13, 1844. 



* ' Familiar Introduction,' p. 144. 



