The early appearance in geological time of terrestrial Arthropods _L has always been to me a subject of deep interest, and I have been fortunate in noticing several of these in the pages of this Magazine and elsewhere. The oldest insect at present recorded is the impression of an Orthopterous wing referred to the family Blattidæ:, obtained from the Silurian sandstone of Jurques, Calvados, France, about the horizon of the May Hill Sandstone (Middle Silurian). M. Charles Brongniart, its discoverer, observes that what is especially remarkable about this fossil, and which distinguishes it from all other Cockroach-wings, living or fossil, is the length of the anal vein, and the narrowness of the axillary area.

The French Geological Society last year made Finistére the object of their annual excursion, and bjr their kindness I had the great pleasure of joining the party. As Brittany is so interesting a region, already very accessible by railways, and soon to become even more so, it has occurred to me that a brief account of the excursion may be acceptable to our English geologists, and at any rate afford them an index to some localities which will well repay a visit.

In the very valuable work on “British Petrography” by my friend Mr. J. J. II. Teall, nowinprocess of publication, there is a rather full notice of an interesting serpentine which occurs in the Rauenthal (Vosges), and has been investigated by Herr Weigand. According to the latter author, as summarized by Mr. Teall,2 this serpentine “has been formed by the alteration of a hornblende rook, and the change has been accompanied by the removal of lime and the development of a chlorite, inwhich the original alumina of the hornblende is retained.”

When visiting Whitecliff Bay, Isle of Wight, last September, I was so fortunate as to find exposed on the shore at low-water, the whole of the various strata from the Brook Bed of the Bracklesham, to the Bembridge Limestone inclusive. I have visited this locality many times, but have never before seen the Barton Series exposed.

Until the appearance of the article by Messrs. C. Iieid and G. Sharman in the Geological Magazine for February, 1886, p. 55, no one had ever thrown a doubt on the existence of true Gault in Norfolk.

The appearance of Professor Bonney's letter in the December a Number of the Geological Magazine, inwhich he suggests that Mr. J. J. Harris Teall's proposed explanation of the cause of the foliation of the Lizard gabbro “ought to be regarded as an hypothesis on its probation, and should not be quoted as an undoubted fact,” emboldens me to offer some remarks on the subject.