INSECTS not to be found in Cambridgeshire, and except perhaps in the case of L. muscerda, nowhere else in the United Kingdom. Calamia brevilinea has a wonderful, and even a rather complete history, so far as the history of any species can be completely worked out. It appears certain that it had no existence in Ranworth Fen at the time, forty years ago, when W. Winter collected for two or three years largely there, sending his captures to purchasers everywhere, and showing himself to be a very skilful and accurate collector. In 1864 the first specimen was captured in the same fen, and after much hesitation and enquiry was described and published as a new British species. Several years elapsed, and then another was taken, and immediately afterwards a few more ; after this it steadily increased in numbers, until it is now in some seasons almost the most frequent noctua to be seen in an August night, at 'light,' in the fen. Moreover it has now spread to other fens at least ten miles away. Yet no record exists of its occurrence, except as a single example in Belgium, in any other part of the world ! Much the same may be said of the pretty little Sericoris doubkdayana, which I had myself the pleasure of discovering in the same fen in plenty in i8j2, which continues commonly there, but of which I have no certain knowledge anywhere else. Another species of interest is Macrogaster arundinis, which, con- versely, used to be found only in the Cambridge fens, and which I tried to introduce, in the egg, into Norfolk about the year 1868. The capture of two males in the same spot ten years later seemed to indicate success, but no more have been found there ; yet within the last ten years specimens have been secured in other fens at more than ten miles distance, giving colour to the belief that it may after all be one of the ancient inhabitants of the county, hitherto overlooked. Leaving the interesting subject of the fens there is another tract of country to which especial attention must be drawn, that lying around Brandon, Thetford, Watton, Merton, and extending into the west of Suffolk and the east of Cambridgeshire. It is known as the ' Breck-sand,' the soil consisting of sand so loose that a field, if ploughed up in the daytime, may not unfrequently be blown level again by a strong wind in the night. It is understood to be the ancient sandy coast of the sea of the later Post-Glacial period, but now has lost the peculiar botanical features of the sea-coast, except in the existence still in plenty of two species of sea-side plants — a grass and a sedge — yet to all appearance its insect fauna remains unchanged, such sea-side species as Agrotis valligera, Mames- tra albicoloti, Anerastia lotella, Bryotropha desertella, Lita marmorea and Argyritis pictella being still to be found, often in abundance ; and more rarely Agrotis pracox and Mesotype lineolata. All these as is well known are otherwise distinctively the ordinary inhabitants, almost exclusively, of coast sandhills, and most of them are to be found on the present coast of Nor- folk, distant twenty or thirty miles. But this ' Breck-sand ' also furnishes a home to another series of species of even greater attractions, since though well known on the continent of Europe, they are for some reason of too delicate organization to exist at all, or only very rarely, on any 137
