The retirement of Sir William Flower from the office of Director of the British Museum of Natural History, which took place on September 30, after fourteen years of extremely efficient and active service, will be viewed with regret by the great majority of naturalists throughout the country. That he achieved the completion of all his plans would be to claim too much in so limited a period of time, but that he succeeded in illustrating how a Natural History Museum may be rendered attractive to the general public and may also be a place of instruction to the student, no one will deny.

In the year 1857, or thereabouts, a remarkable fossil egg was discovered in the Government of Cherson, in South Russia. The circumstances of its being brought to light were peculiar, and its subsequent history is instructive enough to repay a brief recapitulation, which we give as follows.

The occurrence of certain genera and species of trilobites which are destitute of eyes has long been known, and so much importance was attached by Dalman to the presence or absence of the visual organs that he instituted two principal divisions of the trilobites based simply on these characters. Goldfuss followed the same lines in his system of classification, though he took into consideration also the structure of the eyes; and Emmrich likewise regarded the possession or lack of these organs to be of taxonomic value. Although in modern schemes of classification more stress is laid on other features of the organization, yet with our increasing knowledge of the ontogeny of various species of trilobites it is perceived that the presence, position, and nature of the eyes are points which must by no means be overlooked.

In the Geological Magazine for July appears an article by Mr. Charles Dawson on Ancient and Modern Dene Holes. As Mr. Dawson mentions Essex deneholes, and comes to conclusions contrary to those arrived at by Mr. Cole and myself, the authors of the Report of the Essex Field Club on the Deneholes of Hangman's Wood, near Grays Thurrock, I shall be glad to be allowed space for a reply. For though our views do not appear to be injuriously affected by Mr. Dawson's remarks, yet as the Denehole Report is now more than ten years old it is probable that few of the readers of the Geological Magazine have both seen and remember it. And the impression which the reader would derive from Mr. Dawson's article is, that his Bell Pit hypothesis is something quite new, and therefore unnoticed by us, whereas it was an old view before the Report was written, having been put forward by the late Roach Smith in the Gentleman's Magazine in 1867; and an account of workings for chalk, of the kind described by Mr. Dawson, written by Mr. F. J. Bennett, of the Geological Survey, is appended to the Denehole Eeport.