and countries lying to the southward. The preponderance of southern forms is not so great as in the birds, but when we reflect on the large number of peculiar species, and that the Longicorns of the Atlantic slope of Costa Rica are yet scarcely known, it appears likely that many of the Chontales species will be found ranging southward across the San Juan river, and that the Insect fauna will be shown to have the same relations as the Bird fauna; for, as the Atlantic forest continues unbroken much further southward than northward, so will the insects peculiar to the forest region have a greater range in that direction.

Mr. Hollick has beautifully drawn on wood a few of the characteristic Longicorns of Chontales, all of them, with one exception (Polyrhaphis Fabricii), being as yet only known from that province, but probably extending into Costa Rica.

One of these, the lovely little Cosmisoma Titania, No. 7 in Plate, has been appropriately named after the Queen of the Fairies by Mr. Bates. It was first found by Mr. Janson, junior, who came out to Chontales purposely to collect the insects; and I afterwards obtained it in great numbers. The use of the curious brushes on the antennæ is not known. Another longicorn, about the same size (Coremia hirtipes), has its two hindmost legs greatly lengthened, and furnished with brushes: one I saw on a branch was flourishing these brushes in the air, and I thought at first they were two black flies hovering over the branch, my attention being taken from the body of the beetle by the movement of the brushes.

Another fine longicorn, figured in Plate, Deliathis nivea, looks as if made of pure white porcelain spotted with

Ch. XXI.]

MIMETIC INSECTS.

381

black. It was a rare beetle, one or two specimens each season being generally all that were taken; it was usually found on the leaves of young trees, from twelve to twenty feet from the ground. I have taken the rather heavy-bodied female by throwing a stone at it and causing it to fall within reach, but the male is more active on the wing, and it was long before I could obtain a specimen.

Amongst the insects of Chontales none are more worthy of notice than the many curious species of Orthoptera

that resemble green and faded leaves of trees. I have already described one species that looks like a green leaf,

and so much so that it even deceived the acute senses of the foraging ants; other species, belonging to a closelyrelated genus (Pterochrosa), imitate leaves in every stage of decay, some being faded-green blotched with yellow; others, as in the species figured, resemble a brown withered leaf, the resemblance being increased by a transparent hole through both wings that looks like a piece taken out of the leaf. In many butterflies that resemble leaves on the under side of their wings, the wings being raised and closed together when at rest so as to hide the bright colours of the upper surface, there are similar transparent spots that imitate holes; and others again are jagged at the edge, as if pieces had been taken out of them. Many chrysalides also have mirror-like spots that resemble holes; and one that I found hanging from the under side of a leaf had a real hole through it, formed by a horn that projected from the thorax and doubled back to the body, leaving a space between. Another insect, of which I only found two

MOSS INSECT.

specimens, had a wonderful resemblance to a piece of moss, amongst which it concealed itself in the daytime,