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Show 240 MR. R. SHELFORD ON MIMETIC INSECTS AND [Nov. 4, visible both in a dorsal and a profile view. A species of Oberea near rubetra (6), and probably a form of it, is really intermediate in character between these two sets of mimics, the elytra being brown anteriorly (basally) and black posteriorly. The remaining species of Oberea mentioned in the table mimic the reddish-ochraceous Braconids. 0. insoluta and the species of Nupserha have a pale golden pubescence on the basal abdominal segments, and 0. sp. (10) has a similarly situated greyish pubescence: in every case this coloration is not so effective as the white patches of 0. brevicollis, &c. ; but these unicolorous Obereas are so much more active on the wing, so much more Hymenoptera-like in their actions when resting on a leaf or twig, that when they are alive one is much more apt to mistake them for their models than their bicolorous congeners. In other words, these unicolorous Obereas compensate for the imperfection (from a mimetic point of view) of their coloration by their close approximation to the actions of their models. 0. consentanea (8 & 9), 0. sp. near rubetra (6), and 0. n. sp. (10) have the elytra clothed with a delicate silky-grey pubescence, especially in the posterior two-thirds, the appearance varying according to the position in which the insect is held ; and these species mimic Braconids with the outer third of the wings pale fuscous, the varying reflections of the elytra giving a similar impression to that produced by the semitransparent fuscous parts of the model's wings. Glenea iresine (Pasc.) is a small blue species; the middle third of the elytra is brown, shading anteriorly into blue, posteriorly into greyish white; the model is a small blue Hylotoma, and when the wings are laid back the resemblance between the two species is striking; the blue anterior third of the beetle's elytra corresponds to the posterior part of the Hylotoma's thorax, the brown portion to the abdomen with the superposed wings, the greyish posterior third to the tips of the wings of the model, which project beyond the end of the abdomen. Turning to the family Cerambycidse, we find that the subfamilies CalUchromince and Necydalince present in the reduction of the elytra a marked Hymenopterous appearance. Noth opens fasciatipennis (C. O. Waterh.) has already been figured and described (Trans. Ent. Soc. 1885, p. 369, pi. x.). Notliopeus sp. near hemipterus (Fab.) is a large black species with entirely fuscous wings, and is an admirable mimic of a formidable wasp, Mygnimia anthracinus (8m.), which occurs commonly on Mt. Matang. The buzzing flight and other movements of these two Nothopei are remarkably wasp-like and so completely deceived the Museum collectors that they employed the greatest precautions in transferring the specimens from the net to the killing-bottle. A magnificent new species, described by Mr. Gahan in Appendix II. as Nolhopeus intermedius (Plate X IX . fig. 21), was captured near the summit of Mt. Penrissen together with several of its models, Salius aurosericeus (Guer.) (Plate X IX . 20). |