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Show 1896.] EXPEDITION ON THE LOWER AMAZON. 777 For some reason we did not meet with a single specimen of the well-known " fire-flies " belonging to the genus Pyrophorus, either on the Para River or the Amazon itself, although I believe they were found by Mr. Pickard Cambridge in the forest near Santarem. Fire-flies of the family Lampyridae, however, of which our common English Glow-worm (Lampyrls noctiluca, L.) is a well-known example, visited the ship in numbers by night as we proceeded up the river. They were especially conspicuous in the Monte Alegre furo on the night of Feb. 17, flashing out like sparks against the dark background of trees, and scintillating at intervals as they occasionally floated over our launch. Most of the species collected belong to the genus Aspidosoma, including among others A. maculatum, Deg., and A. hesperum, L. In the campo at Santarem on Jan. 29 we took a handsome species of Dung- Beetle (Phanceus mimas, L.), the passage of some cattle along the sandy road affording us an opportunity of observing the wonderful rapidity with which these beetles appear on the scene and bury themselves wdtbin a few minutes of the requisite attraction being provided for them. The only other insects to which I need now refer are the Dragonflies (Neuroptera Odonata). As might naturally be expected in such a laud of waiters this Order was perhaps more in evidence than any other, and was particularly well represented in individuals, although the actual number of species met with was not very great. Though some of the species, again, were exceedingly beautiful in colour when alive, in size they in no way surpassed our British forms. The remarkable ease with which a Dragonflv, even when coming straight towards his would-be captor, contrives to elude the net is well known ; for some reason I invariably found the rarer species the most difficult to catch; the common ones gave little trouble. I frequently had the opportunity of observing how a Dragonfly drinks ; hovering motionless a foot or two above the water he suddenly makes a sharp dart forwards at it, striking it with his mouth and the underside of the thorax, and at once withdrawing to his previous position; the process is repeated several times. Mimicry.-Three cases of apparently genuine mimicry among Insects, which came under m y notice, seem worthy of mention. The first, which has probably not been recorded before, is that of a small Clearwing Moth (fam. Sesiidae), which is an almost exact replica of a W a s p (Polybla phthlslca, F.), of which I obtained several specimens at Manaos and the Parana de Buyassu. In size and general coloration the two insects are the same, and the pattern of orange and black stripes on the thorax of the W a s p is copied so closely by the Moth that at a little distance it would puzzle even an entomologist to distinguish the two species. Unfortunately, I only obtained a single specimen of the Clearwing; it is not represented in tbe Museum collection, and is very probably new. The second case of apparent mimicry, to which I would draw attention, is that of the Dipterous genus Calobata, alluded to above. |