In reviewing those fossil algae associated with biotic reefs since the beginning of the Mesozoic, examples are discussed of algae showing evolution attributed to reef or peri-reefal conditions, those showing diversification attributed to reef environments, and those with frequent occurrence in reef conditions but with evolution not directly attributable to reefs.

In a paper, read before the Geological Society of London (June 25, 1873), “ On the Glacial Phenomena of the Long Island or Outer Hebrides,” Mr. James Geikie mentioned the occurrence of two descriptions of stony clay in the Long Island. The first of these deposits or “Bottom Till” occupies the low ground of the island, and is derived from the disintegration chiefly of gneissie rocks, and so far as observation went proved to be unfossiliferous. The other deposit was found in the north of Lewis, along the coast, and consists of two beds of unstratified stony clay containing fragments of shells, the lower resting on rock in situ.

The papers on the floras of the Carboniferous rocks, published in recent years by Dr. Emily Dix [7, 8], collectively form an important contribution to our knowledge of British Carboniferous palaeobotany. In these publications a floral classification was proposed for the Carboniferous strata of the Swansea district and an endeavour was made to apply it to other British and to foreign coalfields. The present writer, however, considers that some modification of the suggested scheme is necessary in regard to the strata included in the Yorkian Stage. Until this is done the classification will not be applicable to areas outside South Wales.

In his valedictory address as President of the Edinburgh Geological Society, at the close of the session 1879–80, Mr. Milne Home reviewed our recent paper on “The Glaciation of the Shetland Isles.” In his address he not only called in question our conclusions regarding the direction of the glaciation of these islands, but likewise referred to the discordance between the observations of Mr. C. W. Peach and ourselves. As much of this adverse criticism is based on a misconception of the real nature of the evidence bearing on the question, we are anxious to reply to some of the points in the address which might mislead those who are unacquainted with the subject.

Although the lakes and larger tarns of the English Lake District have been the subject of much discussion and have given rise to a very voluminous literature, comparatively little has been written on the smaller tarns, and especially on those of the very smallest size, which are so abundant in many parts of the district. It seems to us, however, that the smaller ones are quite as deserving of consideration as the larger, since they present similar phenomena, and their interpretation gives rise to similar difficulties.

In connection with the revision of the Silurian area in Ireland, at present in progress by the staff of the Irish branch of the Geological Survey, a number of rock-specimens of the dykes occurring on the coast of Co. Down were lately petrographically examined by the writer, who detected in one of the slices a blue amphibole of secondary origin. As a mineral of this kind was not hitherto known to occur in sitû in Ireland, it may be of interest to put its discovery on record here and to give also a few details respecting its characteristics.

Hitherto I have been in the habit of referring the Gyracanthus spines commonly occurring in the Borough Lee Ironstone to G. formosus or tuberculatus of Agassiz, being disposed to believe in the specific identity of those two forms, as has already been suggested by Messrs. Hancock and Atthey, and hinted at by Agassiz himself. In fact, the salient point of difference between the two is the greater extent of the tuberculation of the ridges in the latter, while in the former it is principally seen on the proximal parts of the ridges, which, as they converge towards the anterior middle line of the spine, become first simply undulated and then smooth. The original figured specimen of G. tuberculatus is from the Coal-measures of Sunderland; that of G. formosus is from the same formation at Dudley; but though Agassiz refers to it as occurring also at Burdiehouse, in Midlothian, and Burntisland in Fifeshire, it seems to me very doubtful if these Calciferous Sandstone specimens are really the same. And certainly the study of a large quantity of additional material from Borough Lee has convinced me that the species of Gyracanthus characteristic of this Ironstone of Carboniferous Limestone age is specifically different from both formosus and tuberculatus.

The interest of this section lies in its bearing on the theoretical considerations relative to the causes that produced the extensive deposits of Bubble Drift in the South of England.

a. On the east of Carrack Olu Point, a bed of pebbles, 1 foot thick, is shown under Head, at from 2 to 5 feet above high water. The greenstone composing the Point is capped by a Head of yellowish-brown loam with angular fragments of greenstone.

At the British Association Meeting in Dundee, in 1867, the late Dr. Chambers, in a brief paper, called the attention of Section C. to the existence of an “eskar” in the neighbouring parish of Forgan, in the County of Fife. As far as I can recollect or ascertain, the paper said little or nothing about the subject further than describing its situation, and recommending it to the attention of the Section. And I am not aware that the great accumulations of gravel and sand to which Dr. Chambers referred have been made the subject of systematic observation since.

Having nearly completed the manuscript of a catalogue of some of the Orders of Fossil Mammalia in the Collection of the British Museum, I have thought it advisable to give a brief preliminary notice of some rather interesting points in connection with the structure and distribution of a few forms of Carnivora and Rodentia; in which orders I have now gone through the entire collection of specimens. I also notice one specimen to which I have assigned a new specific name; and another which does not belong to the collection of the British Museum. Several of the more interesting specimens will be illustrated by woodcuts in the forth-coming catalogue.

The Isle of Purbeck possesses numerous points of geological interest, and its coast scenery has been celebrated, in conjunction with that of Lulworth, by many writers and artists. The classical work of Sir Henry Englefield, assisted by Webster, in the early part of the last century, served to make known some of the most interesting features of the coast, such as are more or less obvious to all who venture to sail beneath its cliffs. Of late years the geology of the Isle of Purbeck has attracted the attention of the officers of the Geological Survey, and has come in for a considerable amount of description at the hands of H. B. Woodward, Aubrey Strahan, and Clement Reid, in their respective departments. The zones of the Chalk in this region have also been admirably described by Dr. Rowe and his coadjutors, mostly from coast sections.

Growth of the glabella of the trilobite Dalmanitina olini is studied by plotting various dimensions y against the length of the glabellar stalk x which is taken to represent absolute size. The relations are fitted best by linear equations y = a(x + b/a), and for several dimensions the value of b/a appears to be constant. The concepts of absolute and specific growth-rates are discussed in relation to the glabella of D. olini.

The section of Carboniferous Limestone exposed in the railway cutting on the South Wales relief line to the west of Badminton station is a very fine one, being inferior in the Bristol district only to those of the Avon and of Burrington. There is a continuous section from high up in D1 to the top of K2.

In the last Number of the Geological Magazine there is published a paper by Mr. Robert F. Tomes dealing with two Corals from the Silurian rocks of Britain. For the reception of one of these Corals Mr. Tomes proposes to form a new genus under the name of Hemiphyllum.