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leave Llanberis by the lane opposite the Victoria Hotel, and, after passing through the gate at the farther end, we ascend through the plantation, the toughest piece of collar work of the first half of the day's walk. The young larches here abound with many interesting beetles, especially those of the "soldier" family (Telephorida), but as these cannot be called either mountain or moorland insects we must pass them by for the present. And then, having emerged from the plantation, we follow the path--a broad cart-road, through several gates, and reach the open moorland. The course lies nearly due south on the eastern slope of a valley, Cwm Brwynog, the farther end of which we shall see in a short time as a great black precipice, the Clogwyn-dur-Arddu, a precipice which has proved fatal to more than one benighted traveller. Not only are the slopes on each side of Cwm Brwynog covered, in places, with moraine mounds, but at the head of the valley is a fine bloc perché, a mass of rock, estimated by Professor Ramsay to weigh five thousand tons, and evidently a portion of the cliff half-a-mile distant, which has been deposited here by the melting of a glacier.
But long before we come to the Clogwyn-dur-Arddu we may commence our search for beetles. Here, in these rills which cross the path and run down to join the rivulet that feeds the pretty waterfall of Ceunant Mawr, at Llanberis, we may find, by a little patient searching, an interesting individual of the species Elmis aeneus. We select a spot in the most rapid portion of the rill, and fishing out from the water whatever submerged stones there are, may find on the underside, holding tightly to some crevice or irregularity in the stone, the individual under consideration, only one-eighth of an inch in length, and looking like a small seed. We wonder how it is possible for a little fragile insect like this to maintain its position, and not be washed away by the force of the current, for it is always in the most rapid and never in the still portions of a stream that we find him. A pocket lens, however, will show us how beautifully he is adapted for his part, for we find each of his six feet terminating in a pair of long slender hook-like claws, by which he anchors himself to a stone, and there he sits waiting for whatever good luck and the eddying stream may bring him. And so he plays his part! How he obtains air is a mystery, for though in the water he remains stationary for a very long time; indeed, in such a rapid stream, if he once lost his foot-hold, he would stand little chance of remaining a tenant of his native brook; yet immediately the stone to which he is attached begins to dry he scuttles off to look for a wetter situation.
I have frequently searched these rills, and others on Snowdon, but unsuccessfully so far, for three species of beetles, which ought to occur here, for they are found commonly in similar
places about Llangollen and among the Derbyshire hills. These are the Quedius auricomus, Dianous cærulescens, and Stenus Guynemeri, and from their being found only in the moss of waterfalls are known as the waterfall beetles. They belong to a group of the Coleoptera known as the Brachelytra, from the very short elytra, or wing-covers, which, though they leave the greater portion of the hind-body uncovered, protect a pair of filmy wings, neatly folded beneath them, and by means of which the insects can, when necessary, fly to "fresh woods and pastures new." Quedius auricomus receives its specific name-signifying "golden-locked "--from the tufts of yellow pubescence which stud the body; Dianous is of a blue-black colour, with a bright red spot on each wing-cover, and, like Stenus, which is entirely black, except portions of the legs, is a slender, elegantly shaped insect. The chief interest of these beetles, however, consists in their peculiar habitat, for they are never found except in waterfalls, where they live in the tufts of Sphagnum (bogmoss) through which the stream actually flows, and from this they can be obtained by kneading it down with the hands until quite submerged, when, as the moss rises again out of the water, the beetles rush up to the top of the tufts to see what is the matter. They too, probably, like Elmis, obtain a living by picking up stray pieces of decaying animal and vegetable matter which in its progress down the stream has become entangled in the moss which forms their home.
But time presses and we must push on, keeping a sharp look out on all the patches of wild thyme for our great desideratum, Chrysomela cerealis, for upon the roots of this plant the beetle feeds in its larval or maggot stage. While keeping our eyes on the thyme, however, we must not omit to turn over some of the stones which everywhere strew the slopes above and below the path, for beneath these we are sure to find plenty of interesting beetles, mostly of species nocturnal in their habits, which lurk here until nightfall, when they set out to seek something for supper. Here, under the first stone we raise, we find several specimens of a beetle of elegant shape, half an inch in length, of a shining black colour (sometimes blue-black when alive), and with long slender red or black legs, of which he makes good use as he scuttles off to hide himself afresh from the daylight. This is Nebria Gyllenhalii, a very near relative of one of the most abundant of road-side beetles, from small specimens of which it is not always easily distinguished. Nebria Gyllenhalii is usually, though not exclusively, a mountain species, but those which occur in low-lying situations never seem to possess the light, graceful shape of these dwellers among the mists of Snowdon. The influence of altitude upon the variation of plants and animals is a subject which has long occupied the attention of biologists, and here, on Snowdon, we may find, with
a little careful searching, among the Coleoptera of the region, species which are modified in their structure or colour in a manner frequently met with in Alpine beetles, a modification which consists in (1) a tendency to become apterous, and (2) for the colours to be suffused with, or entirely replaced by black. An instance of one of these modifications is frequent under many of these stones. This is Patrobus assimilis, a brownish-black beetle, one-third of an inch in length, with red legs, and the thorax ornamented with two deep depressions. If we raise the wing covers we find that the wings have become quite rudimentary, in fact only appearing as two small scales of membrane quite useless to the insect for the purpose of flight, while in its very near relative, Patrobus excavatus, a species not confined to high elevations, like the one under consideration, the wings are perfectly developed. There seems no reason to doubt that this retardation of development is very largely due to the influence of natural selection, for amid the storms of Snowdon the possession of a pair of well-developed wings might, and probably would, prove anything but a benefit to the individual supplied with them.
Running about among the short turf we are almost sure, if we keep our eyes open, to come across a sparkling little beetle, about the eighth of an inch long, with very prominent eyes, between which are several deep grooves. In colour the members of this genus-Notiophilus-are all bronze with a very high degree of polish, but among those met with, especially if the ground be at all boggy, we are sure to find specimens of a dull black colour, only recognisable after a careful examination of the structure or a comparison of the specimens with others found elsewhere. The members of this genus afford a good illustration of the tendency to melanism seen in Alpine and sub-Alpine Coleoptera.
But here, under this large stone, we come upon a more interesting individual of the beetle tribe than has yet occurred to us, Pterostichus aethiops, about three-fourths of an inch in length, and as black as its specific name indicates. This is a true Alpine species, found throughout the mountain districts of Central Europe, but occurring rarely in Britain except on Snowdon, where it is far from common. Some entomologists consider this an altitudinal form (or race) of the common Pterostichus madidus; but this opinion I cannot support, after an examination of a considerable number of specimens. Along with this beetle we are nearly sure to meet with one or more species of the genus Carabus, a group of beetles distinguished for their large size, and often for their brilliancy of colouring. One of the largest, Carabus catenulatus, common on Snowdon, measures over an inch in length, and is recognised by its wrinkled black elytra, the borders of which, like those of the
thorax, are of a shining violet colour. Like all the members of the genus, this species is apterous, that is, quite destitute of wings, and it has to trust to its long slender legs to enable it to capture the other insects upon which it feeds. Another species of the same genus may also be found here, Carabus arvensis, about an inch in length, with wing cases of a brassy or brassygreen colour. This insect is said to be frequent under stones by the roadside in the Pass of Llanberis, but I can only say that on the single occasion on which I have sought it there the day was so terribly hot, and the stones by the roadside so hot too, that had Carabus arvensis, or any other beetle, been under them, they would have been roasted. As it was, the only living creatures which seemed able to stand the extreme heat of these stones were ants, which were very numerous, and slow-worms. Such a day I hope never again to experience, and I was very pleased to reach Pen-y-pass Inn--rather let us call it by its older name, Gorphwysfa, for a veritable resting-place and shelter it proved this day-from whence we made our way by the Capel Curig path over Snowdon back to Llanberis rather than again face the dreadful pass.
While we have been turning over the stones on the slopes leading up to Snowdon we must have noticed, clinging to tufts of the fir club-moss (Lycopodium selago), a violet beetle, about an inch in length, and of an elongate shape. This is Corymbites cupreus, one of the Elaterida, or "Skip-jack," tribe. These beetles receive their trivial name of "Skip-jacks" from their possessing the power of regaining their natural position, when they have fallen or been placed on their backs, not by means of their legs, as do most beetles, for these are too short, but by bending themselves backward and suddenly throwing themselves vertically into the air, often to a height of six or eight inches, and generally alighting "right side up." This leap they are enabled to accomplish much in the same manner as the jumping frogs one sometimes sees being hawked in the streets of our large towns, the wooden spring of the frog being replaced in the beetle by a dagger-like spine on the under surface of the chest which is suddenly jerked into a groove upon the next joint of the beetle's thorax. The species we have just captured is distinguished for the great development of the antennæ, or horns, of the male, in which each joint is so prolonged at the inner angle that the whole organ looks like a comb, the prolonged joints representing the teeth. Such an antenna is termed pectinate. Usually this beetle has two large yellow patches occupying the hind half of the upper surface, but with a single exception all I have taken on Snowdon were of a uniform violet colour. The larvæ of the beetles of this group often do great damage to our food crops,
and are among the greatest enemies of the agriculturist, who classifies them indiscriminately as "wire-worm."
But we have not yet obtained even a glimpse of our great desideratum, Chrysomela cerealis, and my readers, if ever they go to Snowdon in search of this handsome species, must prepare themselves for disappointment, for not only is the insect excessively local, being confined apparently to very small patches of thyme, patches often at considerable distance apart, būt, also, it only seems to emerge into daylight during the hottest sunshine. And when one does see it, gleaming among the herbage like an animated spark of coloured fire, no matter how fatigued one may be with tramping over the slippery ground, no matter how severe a headache one may have from the hot sun, all these are forgotten in the enjoyment of that moment. Such, at least, has been the experience of the writer. It is said that when Linnæus visited England and saw the gorse in full bloom on our wild Yorkshire moors, in such luxuriance as can scarcely be equalled elsewhere, he fell on his knees and thanked God for the glorious sight. Something like the same feeling of rapture came over me when I first beheld Chrysomela cerealis crawling on a sprig of wild thyme on Snowdon, and the pleasure of the capture was enhanced by the fact that I had spent the three preceding days in an unavailing search for it, days during which I had tramped many miles in the hot sun over the slippery and stony slopes, where I knew it had once occurred, and must, consequently, occur again. The last day of June, 1886, must always remain a red-letter day in my entomological calendar. But I am reminded that I have been expecting my readers to sympathise with my hobby without in the least knowing what Chrysomela cerealis is. Imagine a beetle about one-third of an inch long, oval in outline, and very convex on its upper surface. This upper surface is formed, as in all typical beetles, by a coat of mail of such density as to be pierced only with difficulty, but of such exquisite polish as to rival the finest productions of the silversmith. The head is brilliant emerald green, with two spots of fiery copper; the thorax is of this same fiery copper with three stripes of intense purple-blue, the colour fading at the edge of each stripe into peacock-green; while the elytra, or wing covers, are coloured with alternate longitudinal stripes of fiery copper, peacock-green, golden-green, and violet blue. But even the most accurate word-painting, aided by the finest drawing, will give but a meagre idea of the exquisite loveliness of this beautiful creature when seen crawling about, in and out of the tufts of wild thyme. Alas! the extreme brilliancy of its colour becomes lost after death, although even then, when mounted on card and placed in one's cabinet drawers, it remains "a thing of beauty" and "a joy for ever."
And now, having introduced my readers to a very few of the