40 NATURAL HISTORY OF WASPS. 
common to the other tree-wasps as well as to V. rufa 
also. Again, the yellow lines which converge from 
the root of the wings on either side to the back of 
the head, the yellow triangular spots beneath the 
wing's, and the yellow line visible on this aspect behind 
the upper limb of the compound eyes are common 
to all the species. They are of use in distinguishing ° 
these Vespze from others, but between one British 
species and another they have no significance. 
The truncated end of the abdomen is black, and a 
band of this colour is extended a little beyond the 
square edge where the dorsal aspect begins. In the 
middle this black marking comes down in an obtuse 
angle. At the sides it slopes off in an even line, 
except where it is encroached upon by an orange- 
coloured spot. The yellow border of this ring has 
also a very decided orange tint. The second ring, in 
the same way, presents a bluntish cusp in the centre, 
but, instead of narrowing from this point, the black 
band sweeps down, in a saddle shape, to the two 
lateral cusps, which are square, not pointed, at the 
end. Then it suddenly turns up, and in the notch 
thus made a bright orange spot is generally to be 
seen. The central cusp disappears in the succeeding 
rings; and, as the band becomes narrower, the ends of 
the lateral ones are disconnected with it and stand 
out as isolated black spots on the yellow ground. 
The male has the same markings on the face and 
thorax as the female. But the orange spot on the 
second abdominal rmg is more decided in this sex. 
The black bands are of a more uniform width, and 
their outline is less broken by the projecting cusps. 
Sometimes the female of this species is covered with 
