V. arborea, Plate III, is represented in my cabinet, as in most others, by the female only. She is shorter and not of such elegant proportions as V. sylvestris. The clypeus is marked by three little streaks, radiating as it were from the upper edge of the commissure of the mandibles, the central streak being the smallest. There is a yellow line just edging the lower limb of the eyes. The corona is large, deeply notched in the centre, and with a smaller notch on either side on the upper edge; the sides are straight, converging to the lower edge, which is slightly hollowed out.

The thorax is marked as in the two preceding species, but the markings of the abdomen are very peculiar, resembling closely those of V. rufa. But while in this the orange yellow, as its name indicates, is very decided, the gamboge hue is more distinct in V. arborea than in any other of our species. The first abdominal ring presents three transversely-oval black spots, which are sometimes connected to each other by a faint shade. The lateral spots are isolated, but the central spot is connected by a root with the central cusp of the dark band which just shows over the square edge of the upper portion of the abdomen. In the second ring the black band is spread out into a central cusp, on the top of which stands an oval spot like a button on a cow's horn. Below, on either side, is an oval spot, corresponding to those noticed on the first ring, but very much smaller, and, as in the species already described, rapidly disappearing in the succeeding rings. An indistinct shade connects these spots with the central cusp, and sometimes a faint line runs up from them towards the sides,

enclosing a diamond-shaped space, similar to what we find so strongly marked in one variety of V. rufa. I am indebted to the kindness of Mr. F. Smith on this as on so many other occasions, for the opportunity of completing this series of illustrations from his specimens of the male and worker of this rare species. It will be seen, from the drawings, that the markings of the male differ little from those of the perfect female. In the worker the distinctions are more marked, the central spots or buttons on the abdominal scales being drawn out, as it were, into angular cusps, somewhat in the way that we shall find those of the worker of V. rufa to be.

Turning now to the ground-wasps :

V. germanica, Plate III, in the person of the queen, attains perhaps a larger size than any other of the small British wasps. She herself is at once distinguishable from the queen of V. vulgaris, but the males and workers of these two species are not always easy to be known apart. The clypeus has three black spots, but the middle one often exceeds the rest in size, descending from the top of the clypeus as a broad black line. Instead of her having only a narrow edging to the lower limb of the compound eyes, nearly the whole space between the limbs is filled in with yellow. The corona seems to spread out into two horns, the upper edge being widely hollowed out; the sides descend straight, slightly converging; and the lower edge is concave, with a central angular notch.

The thorax presents four yellow spots, two on either side of the metathorax, the hinder pair being

much the smallest. In this species, as in V. arborea, the black band scarcely reaches beyond the edge of the dorsal aspect of the first abdominal ring. The broad yellow dorsal surface is broken by three black spots. Of these the central spot is the most conspicuous; it is diamond shaped with the angles somewhat rounded off, and extends quite from one edge of the ring to the other. The lateral spots are oval, closely attached to the black band, and not extending as far as the central one towards the edge of the ring. In the second ring a narrow black band appears on the dorsal surface which rises in the middle into a long dome-shaped cusp bulging out at the sides. The two lateral spots are round, and quite unconnected with the black band. In the successive rings the lateral spots stretch out into transverse streaks, while the central cusp is thinned down into the more usual pointed form, hollowed out at the sides.

The markings of the abdomen of the worker differ notably from those of the queen. The diamond in the centre of the first abdominal ring is smaller in proportion, and the angles sharper; the lateral spots are also smaller, and more distant from the

In the succeeding rings the same sharpness of the angles appears, the dome-shaped central marking on the second having the outline often broken by the projection of a point on either side. The markings on the male are still smaller in proportion than those of the worker, especially those on the first abdominal ring. Their form is intermediate between those displayed in the queen and the workers respectively.

V. vulgaris, Plate IV, is sometimes most inconveniently known by the name of the anchor-faced wasp, from the form of the markings on the clypeus. She shares this appellation with V. rufa. There is a broad line down the centre of the clypeus, swelling out at the bottom on either side into a form more resembling the battered head of an old wedge than the arms of an anchor. Sometimes the black marking stops here, at others it contracts into a narrow line which is continued down to the lower edge of the clypeus, as in V. britannica.

The corona is large. There is a deep central notch on the upper edge, which curves outwards from this point in a continuous sweep. The sides are straight, and so are the two lines which, meeting in a shallow central notch, form the lower boundary. The form of the corona, however, like that of the marking on the clypeus, varies considerably in different specimens. One of the most common varieties is the presence of two little cusps, or perhaps isolated dots, beneath the lower edge. As in V. germanica, the space between the limbs of the compound eyes, in front of which the scape of the antennæ lies, is uniformly yellow.

The metathorax is marked with two, or sometimes three pair of symmetrical yellow spots, rather smaller than those which are found in the species last described.

The first ring of the abdomen has a broad black band curving down regularly to a central point, the outline unbroken by any projecting lateral cusps. The markings of the second ring much resemble those of the hornet, and, as in that species, there is

an alternation of light and shade; the black polished band which underlies the preceding segment being followed by a lighter coloured band before the distinctive marking begins. A central point and two lateral square cusps distinguish this species; the point shrinking, and the squares separating from the black band, in the succeeding rings.

There is no difficulty, as has already been said, in distinguishing the queens of V. vulgaris and V. germanica from each other, but the males and workers are not always readily to be referred to their respective species. The first segment of the abdomen in the worker of V. vulgaris displays only a very narrow black band on its dorsal aspect, and the central marking is diamond-shaped, with the lateral angles much elongated. In some workers of the two species the markings of this ring are absolutely the same. The saddle-shaped marking, which begins in the second ring of the queen of V. vulgaris does not begin till the third ring of the worker; and that which this worker usually bears in her second ring is very like the marking of the worker of V. germanica. The male would be still more difficult to distinguish did not the form of the sexual organs supply an unerring differential character under the microscope. When V. vulgaris has her typical saddle-shaped mark on the third ring, and that on the second ring of V. germanica does not deviate far from the figure of a dome, there is no difficulty; but when the black central mark shrinks in the first- and spreads in the last-named species, and the lateral marks of V. vulgaris

*

• Smith. · Catalogue of British Hymenoptera,' 1858. Vespidæ, Plate V, figs. 20, 21.