212 THE ENTOMOLOGIST. 
Social Wasps,’ and another on plate x. Mr. Eedle’s speci- 
mens closely resemble the latter: they are attached to the 
common ling and heather so firmly that it would be next to 
impossible to remove them without injury. This species has 
the abdomen distinctly banded with black and yellow. I 
commonly find this species of wasp at the blossoms of the 
figwort (Scrophularia aquatica), and, by a singular coincidence, 
the Tenthredo Scrophulariz of Linneus, a species similarly 
banded with black and yellow, and equally conspicuous, is 
also confined to the same genus of plants, the larva feeding 
on its leaves, the wasp on its nectar. Can the theory of 
mimicry help us here? Turning to Mr. Smith’s ‘ Catalogue 
of Fossores,’ I observe he says this wasp is very partial to 
the flowers of Ballota nigra; a fact I have never noticed.— 
Edward Newman. 
H. J. H.—The hair-worm (Gordius aquaticus) is the adult, 
and not the larval state, which is singularly unlike the speci- 
men sent: it is very short, being described as 34, of an inch » 
in length. I cannot pretend to any knowledge of this from 
personal observation. The female Gordius deposits her eggs 
in the water in long strings. I have lately seen specimens of 
this strange creature six inches in length, and not much 
thicker than a horse-hair: indeed, country people have often 
supposed, and asserted, these hair-worms to be horse-hairs, 
which had fallen into the water, and so become animated. 
When the rain came, after the late dry weather, I found these 
Gordii on strawberry-leaves, currant-bushes, rose-bushes, &c. 
very abundantly, tying themselves in most. marvellous knots ; 
and I have attempted in vain to explain that they did not 
fall from the clouds.—EHdward Newman. 
A. Hamilton.—In the ‘Entomologist’ (Entom. vil. 137) 
I find mentioned the parasite of the ow], and having caught 
a specimen this morning on a fern owl, I have great pleasure 
in forwarding it to you: the shuffling disappearance of the 
creature, remarked by your correspondent, describes its 
movements accurately. As I shall most likely have many 
opportunities of searching owls, I should like to know if you 
would like the specimens in spirit, or as I have sent the 
present one.—A. Flamilton; 138, Park Street, Windsor, 
August 18, 1874. 
[The insect is Ornithomyia avicularia: it seems a very 
