It was stated in the general introduction to these Contributions (GEOL. MAG. June, 1880), that the divisions to be adopted would be regarded more as a matter of convenience than from any other point of view. It might, perhaps, seem more philosophical to have treated the whole of the Lower and Middle Oolites as one section of the subject quâ the Gasteropoda. By commencing at the base of the series the true sequence in time would have been followed, and the various “species” or their derivatives traced throughout. Had all the collections examined by me existed under one roof, this might have been practicable, as it would certainly have been desirable.

I Regret that in consequence of the omission of a correction in my letter (GEOL. MAG. Dec. 1881), I represented Dr. Callaway as stating that the Nebo rock was granitoidite instead of a part of the granitoidite series. When the letter was written, I was not able to refer to Dr. Callaway's paper for his exact words, and on seeing the paper two or three days later, and finding that I had not given accurately the words, I wrote at once to the Editor of the GEOLOGICAL MAGAZINE, asking him to substitute for the word “granitoidite” the words “Pre-Cambrian rock.” By inadvertence this was not done, and as proofs of letters are not usually sent to authors for correction, I found that the alteration had not been made when the December Magazine appeared.

Mr. A. Champernowne having requested me to examine and briefly notice some fossils in his collection, obtained from the Red Homalonotus Beds of the Lower Devonian, Torquay, I have endeavoured to comply with his request so far as the condition of the specimens permits. Besides the Homalonotus remains, there are a number of Mollusca preserved as casts, but, for the most part, so distorted by slaty cleavage, as to render their determination most difficult.

In the Geological Magazine, November, 1881, I published a brief description, accompanied by a Plate, of a new species of spinose Homalonotus, which I named after its discoverer, H. Champernownei.

On the accompanying Plate IV. Fig. 3, 1 have given an illustration, of the tail probably referable to the above-named species.

As this subject has been a matter for considerable debate during the past few years, and the British Committee of the International Geological Congress have had the matter under their consideration, it may be useful if I attempt to place before the readers of the Geological Magazine the results of the investigations of our sub-committee. As is well known, the term “Poikilitic” has been proposed in some quarters as a comprehensive name for both series, some writers advocating the view that they ought to be regarded as one “system,” as indeed they were of old under the name “New Red Sandstone.”

It is not a little curious that twice in five years the British Islands have been visited with meteoric falls; in each case a single specimen has been found and, the one a small block of iron, the other a small block of rock, they constitute the prettiest little cabinet specimens of the two chief typical classes of meteorites. The former fell at Rowton, in April, 1876; the other near Middlesborough, in Yorkshire, on March 14th, 1881, and will be described later on.

We now enter upon the third and concluding term of Linnarsson's geological career. This extended from the commencement of the year 1876 to the date of his untimely death in September, 1881. Hitherto, he had been occupied mainly in the development of the grander natural divisions of the Lower Palæozoic Succession of Sweden. This final period was devoted to the task of elaborating their minor subdivisions and best-characterized zones of life.

Prof. Prestwich, in his paper in the January Number of this MAGAZINE on the “Causes of Volcanic Action,” assumes the existence of hot reservoirs or cavities filled with molten rock, and cold reservoirs or cavities, nearer the surface, filled with water; and he supposes the shrinkage of the Earth to squeeze up the molten rock till it meets with the water, which then explodes, producing a volcano.

p. 94, line 10 from bottom, for “Upper White Lias,” read “Upper Lias.”

p. 96, for “Transactions of the Bath Literary and Philosophical Association,” read “Proceedings of the Bath Natural History and Antiquarian Field Club.”