3S8 HYMENOPTERA ACULEATA. 



Barbutellus, the apex of the abdomen being clothed 

 with yellow hairs, more or less widely interrupted down the 

 centre ; a quite black variety, however, sometimes occurs. 

 The following structural characters will distinguish the 

 species in all its varieties : — 



(^ with the fourth joint of the antenna very slightly 

 shorter than the third, fifth about two-thirds as long as the 

 third and fourth together; sixth ventral segment slightly 

 channelled down the middle, without apical tubercles, each 

 side bearing a tuft of long black hairs, armature with the 

 Bagittse strongly hamate beneath, the laciniae very broad and 

 triangular, their inner margins straight, meeting each other 

 in parallel lines. 



? with the sixth ventral segment narrowly rounded at 

 the apex, its posterior margins with very wide callosities 

 which nearly meet apically, leaving a long apical sulcature 

 between them. 



L. 17-20 mm. 



Generally distributed, associating, according to most 

 authors, with B. muscorwri, but according to Smith with 

 hortorum and Latreillellus. The general coloration and 

 variability of the species would rather suggest the associa- 

 tion given by Smith ; possibly, however, it associates with 

 both. 



P. quadricolor, Iiep. {Barbutellus, Smith). — Coloured 

 much as the preceding, but differing in the following par- 

 ticulars : — 



^ with the third and fifth joints of the antennas subequal, 

 fourth about two-thirds as long as the fifth ; abdomen shorter, 

 less pointed, apical half of the third segment and the whole 

 of the fourth clothed with white hairs, fifth with black, sixth 

 and seventh or rarely the seventh only, with rufescent 

 hairs ; seventh ventral segment simple, lacinia of the arma- 

 ture very long and narrow, many times longer than wide. 



? Smaller than any of the preceding, abdomen looked at 

 from above more rounded, apex clothed with white hairs, 



