It has become increasingly evident during the past few years that there are many geologists working on the older Palaeozoic rocks in various parts of the British Isles, to whom a knowledge of the common assemblages of graptolites characteristic of our different British graptolite zones might be useful. In the following lists, therefore, an attempt has been made to put together the facts gleaned from the study of the Graptolite Shales of the British Isles in many widely separated localities. The lists do not claim to be in any way a complete representation of the entire fauna of any zone, but merely an enumeration of those graptolites which in the author's experience are most universally and abundantly represented, so that they are likely to be the forms met with most characteristically in an exposure of any particular horizon. Some co-mingling at the boundaries of the zones must naturally be expected, especially when dealing with a succession of purely shaly deposits, but as a rule even then the coming in of new forms in abundance should be taken as an index of the passage to a higher horizon. This fact is one upon which great emphasis should be laid, it is upon this coming in of new forms, usually indicative of a more advanced stage in evolution, that the basis of modern zonal stratigraphy is laid; the persistence of old forms tends to vary greatly in different localities with the richness of the previous fauna; when the fauna of the earlier zones was both rich and varied, there are naturally more survivors into the succeeding zones than when the fauna was a poor one.

In 1900 Mr. R. Bullen Newton described the casts and impressions of some lamellibranch shells, in blocks of fossiliferous sandstone from Kuala Lipis, Pahang.1 On account of the prevalence of specimens which he assigned to the genus Myophoria, Mr. Newton called the rock “Myophorian Sandstone”. Amongst other species identified by Mr. Newton Chlamys valoniensis has a wide distribution, “and is characteristic of the Ehaetic or uppermost Trias. It is to this horizon, therefore, that the Myophorian Sandstone must be referred”.

The three species of corals which form the subject of this communication are all from the Lower Lias of the west and centre of England. They were originally described by Duncan3 as species of Montlivaltia, viz. M. rugosa, M. mucronata, and M. victoriae. But in 1890 it was suggested by Freeh4 that many of the so-called Montlivaltia and Thecosmilia from the English Lias should be included in the genus Stylophyllopsis, established by him in that year for certain Triassic corals which possessed in their septal structure, and in other features of lesser importance, characters sufficiently distinctive to justify their separation from Montlivaltia. Owing, however, to the absence from Duncan's monograph of satisfactory representations of transverse and longitudinal sections, the generic determination of the English forms remained in every case uncertain.

In previous papers1 the assemblages characteristic of the systems lime-magnesia-silica, and magnesia-alumina-silica, in thermal metamorphism have been described, special reference being made to the range of mineralogical associates of rhombic pyroxene.

The question of the zinc content of the Ballachulish granodiorite (Geol. Mag., Dec, 1924, p. 554) has now been thoroughly investigated, Dr. E. G. Zies, of this laboratory, having very kindly interested himself in the matter.

Along certain of the coast sections in the province of Manabi, Ecuador, a series of large igneous boulders (of a coarse granitic type) occurs in situ among normal Tertiary sandstones. Tertiary sediments form the greater part of the “littoral” or coast belt of this country. One of the masses of rock referred to above had a weight, at least, of twenty tons—an exceptional size for an undoubted constituent member of a sandstone or a conglomerate.

Although the full account of the Geological work carried out by the St. George Expedition to the Pacific must await the working out of the specimens collected, the following brief preliminary notes may be of interest.