Page:The Zoologist, 1st series, vol 4 (1846).djvu/70

1236 Dr. Harris says that it lays its eggs on the catei-pillars of butterflies, but I believe that it more often pierces the chrysalis while yet soft.— Francis Walker; Grove Cottage, Southgate, December, 1845.

Distribution of the species of Harpalus and Ophonus. — In the neighbourhood of Leicester we find but four species in all, of the genera Harpalus and Ophonus ; which, considering there are no less than sixty-three recorded as indigenous to Britain, seems to indicate a strange deficiency in some of the local circumstances favourable to their existence. The species are Harpalus limbatus, aeneus and ruficomis, and Ophonus punctatissimus, and of these H. limbatus and O. punctatissiraus are rare and local ; the latter shewing also, a great deterioration in the size and condition of the individuals. The causes of this are to be sought I think, chiefly in the nature of the soil of the dis- trict; which, — excepting in the immediate neighbourhood of the sienitic rocks of Chamwood Forest, where, being the powderings of those old, weather-worn clifis, it is light and sandy — consists of stiff" clayey earth and the marls of the new red-sandstone. The Geodephaga are peculiarly the creatures of the soil, and are influenced by it per- haps more than any other tribe of insects. Here, in the winter they are unable to bur- row or find a genial abode for their hybernation in the earth, and the peculiar species that do flourish here, as the Agona and other damp-lovers, retire to the bark and roots of willows. On the light sandy and chalky soils of the South of England the Harpali and Ophoni have their metropolis : last May, during eight days research in the Isle of Wight, I took at least twenty distinct species of these two genera, which number has been much increased by the Rev. Mr. Dawson of Ventnor, and they were the common- est insects. The most conspicuous were Harpalus serripes, tardus, anxius, thoracicus, cupreus, azureus, rubripes, marginellus, fulvipes, annulicornis and Ophonus obscurus, nitidulus, azureus, punctatissimus and puncticollis. The Harpali are very sensitive of cold, the gentleman above-named notices that on colder days, even in August and Sep- tember, they burrow to the depth of several inches in the sand. The proximity of the sea, I think is not a cause of any great influence in the distribution of these insects, as I am told there exist but three species even in the neighbourhood of Newcastle, and the neighbourhood of Hertford in a cultivated country appears to be almost as rich as the broken, rough and sunbaked shores of Dover and the South coast of the Isle of Wight. The distribution of insects in Britain, and the laws which govern it have certainly not been much studied with us, although it is true that our Island forms but a northern por- tion of a greater Zoological province, yet the relative peculiarity of the productions of the south from those of the north, will perhaps hereafter be found to be much greater than was suspected. The fashion has been almost universally, to append a list of localities to a species without any distinction between its rarity in one place and abund- ance in another, or inquiry how far different local circumstances affect its habit or con- dition. A species is originally discovered, prolific for instance, in the low country of the " Bedford level." Afterwards a few individuals may be taken in Norfolk, Suffolk, or the " London district," or a starved specimen in Wales or Scotland. These habitats are then strung together without any distinction, and the purposes of science are not served. Entomology may supply facts towards generalizations on the subject of geographical distribution of great importance to science at large, and such researches are pursued on the continent with some fruits, if we may judge from Dr. Erichson's re- port in his 'Archiv.' (Translated and published by the Ray Society.) — H. Walter Bates ; Leicester, November 19th, 1845.