The Geological Magazine for October last contains a criticism by Mr. David Forbes of certain views put forward by me ina lecture delivered before the Royal Institution of Great Britain on the 31st of May, 1867. Of this lecture a short-hand report appears in this Magazine for August, besides which a condensed report, revised by myself, is published in the proceedings of the Institution, in the Chemical News for June 21st; and in three French translations in the Revus des Cours Scientifiques, Les Mondes, and Cosmos. The Chemical News for October 4th contains a criticism of my lecture by Mr. Forbes, to which I have replied in a communication recently addressed to that Journal.

In the “Canadian Naturalist and Geologist,” vol. iv. p. 134, figs. 8–9 (1859), I figured a small specimen of a species of Stricklandinia under the name of S. lens; but, at the same time, stated that I was not certain whether it was the true S. lens or a variety. It was more pointed in front than any of the English specimens I had seen. It had been collected in the Middle Silurian rocks on the Island of Anticosti, along with numerous other specimens, most of them in a fragmentary condition. Among these I thought that S. lirata could also be identified; and thus both of the British species have been cited in several of the publications of our Survey.

Having lately read some interesting remarks on the well-known green-coated flints of Kent in the Geological Magazine, I am induced to offer you the following notes.

During the summer of 1864 I investigated many parts of Bulgaria, but more especially the Dobrudscha, where the sagacious observations of Capt. T. Spratt, R.N., F.R.S., frequently served me as guides. In the highly interesting Cretaceous strata at Kanara, near Küstendsche, which had been correctly identified by Capt, Spratt as Chalk, and from which Professor Reuss lately described many Foraminiferœ I discovered a pseudomorphous substance, which replaces the flint at many points along the coast, and in the Kara-Suvalley.

It is of the first importance in Natural History to adopt a precise, and if possible a received terminology, and strictly to adhere to it. From the very different opinions that have been entertained regarding the nature of graptolites, a curiously mixed set of terms have been employed on their description, some being suggested by their supposed resemblance to plants, others being obtained from their affinities to animals. Discarding these I shall employ the terminology proposed by Allmann and Huxley for the Hydrozoa now generally adopted, asking the reader to take here for granted what I hope presently to establish, that these fossils have their nearest allies in this class, and consequently that the terminology is suited equally to both. As the terms, however, have not yet been generally introduced into text books, it is perhaps desirable to give definitions of those that I shall have to use in this paper.

The accompanying figure (1) represents a fossil in my possession obtained with some insect remains, by Mr. W. R. Brodie, of Swanage, from the Lower Leaf-bed of the Lower Bagshot beds, Studland Bay, Dorsetshire. It bears a general resemblance to the examples found by Mr. W. S. Mitchell, at Alum Bay and Bournemouth; and to those figured by Heer as Porana (Flora Tertiaria Helvetiæ, plate 103), from the Swiss deposits, except in its havingbut four instead of five lobes. It resembles somewhat in outline the recent Porana volvbilis, and, as the absence of the fifth lobe might be merely an abnormal Condition of the individual example, it seemed, at first, scarcely sufficient to separate it from the genus with which all the other similar forms from the Tertiary bedshad heretofore been identified.