HALICTUS. 219 



brought them forth in all the beauty of their gay attire, 

 and that it was from their broods deposited thus in the 

 spring and early summer, that the autumnal insects 

 were developed. This theory is both plausible and pos- 

 sible, and I have no doubt that it is the correct one; and 

 thus is explained the total absence of males at the time 

 of the appearance of the females in the foremost portions 

 of the year ; this habit we shall find also in the Bombi. 

 The flowers they delight in, besides those previously 

 named, are among others the ribwort plantain, and the 

 bramble, as well as the Umbelliferce and the flowers of 

 the broom. The females possess two remarkable dis- 

 tinctions of structure not found in any of the other bees, 

 which consist in an articulated appendage in the centre 

 of the front margin of the labrum, and a vertical cleft in 

 the terminal segment of the abdomen, both of which 

 will necessarily have their uses in the economy of the 

 insect, although what these may be has not been dis- 

 covered. 



They, like Andrena, are exposed to parasites and 

 enemies. The smaller species of Nomada infest their 

 smaller kinds, and St. Fargeau tells us that the Sphe- 

 codes are also parasitical upon them. The smallest of 

 the genus, which is indeed an exceedingly minute insect, 

 is subject to a very minute strepsipterous destroyer; 

 whether this be a genuine Stylops I am not aware, but 

 the supporting insect being so minute, in fact the 

 smallest of our bees, how small must be the enemv bred 



ti 



within it ! Another genus of this order has been found 

 by Mr. Dale upon them, and which is figured as the 

 genus Elenchus in Curtis's ' British Entomology.' The 

 smaller species are also attacked, upon their return home 

 laden, by spiders and ants. Chryses and Hedychra are 



