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 



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