The material upon which the following descriptions are based was obtained chiefly by Mr. Ussher, who collected the Whiteway and Hestow Farm specimens. The Daymer Bay form was collected by Mr. John Pringle. For the new species of Proetus I am indebted to Mr. Claude H. Peter, Town Clerk, Launceston, who, through Mr. Clement Reid, kindly lent it for description. It is evident from the examination of this limited quantity of material that the British Devonian fauna is not yet fully known. We may expect the discovery of many species hitherto unrecorded in this country, which will be of interest from the possible comparative relationship with the fauna of foreign deposits. The accompanying illustrations were drawn by my colleague, Mr. H. H. Thomas, to whom I tender my best thanks.

Mr. T. Mellard Reade evidently wished to clicit, by his note on the mechanics of overthrusts in the Geological Magazine, 1908, p. 518, a discussion on these phenomena, as he also tells us in the February Number, 1909, p. 75. May I be allowed, therefore, to contribute some remarks on his paper?

Mr. P. G. H. Boswell, F.G.S., has kindly submitted to me a crinoid fragment found by him on August 20, 1908, in the Red Crag of Felixstowe cliffs, Suffolk. Although the specimen is somewhat obscure, it is of sufficient interest to warrant a brief note.

Before the beginning of this year the only records of the occurrence of fossil marsupials in Western Australia consisted of the account of the discovery of Diprotodon bones in the Kimberley district by Mr. E. T. Hardman, the Government Geologist, in 1882, and the finding of a lower jaw of this animal in 1895 in a gully near Lake Darlot in the Eastern Goldfields by Mr. Arthur, who presented it to this Institution. This jaw was so much weathered that it was valueless except for the fact of its establishing the existence of that marsupial so far inland. The Museum Committee sent an expedition to Lake Darlot in 1898, and in 1908 the Hon. Dr. Hackett sent out at his own cost Mr. Young, who was with Mr. Arthur when he found the jaw in 1895. Both these parties were unsuccessful.

In a paper read at the 1903 meeting of the British Association and afterwards published in this Magazine, the method of calculating the chemical constitution of the igneous rocks by the collation of analyses was criticized, and the results were compared with those based on actual field-work in an area where such rocks were very abundant. Mr. F. W. Clarke, whose results and those of Mr. Harker had interested me in the problem, has recently published a fresh calculation of the results of the rock analyses made in the Laboratory of the United States Geological Survey. It is not proposed to discuss these results in detail, and it will suffice for my present purpose to take the question of silica percentage alone. Mr. Clarke's average for all the 1,358 rocks analyzed up to the end of 1903 works out at 60·91. Mr. Clarke, however, admits that the ‘salic’ rocks are more abundant than the other classes, and he further grants that my criticism of his previous results is entitled to some weight, though he thinks that a wider range of observation would probably modify my opinion that granite is practically the average igneous rock.

One of the most interesting and most vexed questions in vertebrate palæontology at the present day is the one which concerns the origin and development of the reptiles. The progress of research has shown the Reptilia to be a wonderfully diverse class, and nearly thirty orders of animals have been assigned to the group. With all this diversity of structure there is, of course, associated a great diversity of habit. We know all kinds of extinct reptiles from the semi-aquatic to the aquatic, from the flying to the fossorial, from the arboreal to the subterranean, and many are the varying degrees of structure which are associated with these various habits of life.

During the past year several igneous erratic boulders have been noticed on the cliffs of South Pembrokeshire by Mr. A. L. Leach and myself, in situations where no such erratics were previously known, so that a record of the larger ones seems advisable; five of them being dealt with in the following paper. At Mewsford Point, near St. Govan's Head, there is a well-rounded boulder measuring 4 ft. 1 in. × 2 ft. 6 in. and about 2ft. 6in. high, weighing approximately 32 cwt., and visible from some distance because its outline and dark colour differ markedly from the surrounding crags of Carboniferous Limestone. It appears to be the southernmost igneous erratic boulder in Pembrokeshire, and hence is of more than usual interest.

In a denehole at Abbey Wood, near Plumstead, there is shown in the Chalk a fault of unknown extent (but probably having a throw of only a few inches), the plane of the fault roughly coinciding with one of the chamber walls. This wall has a strongly slickensided surface for some superficial yards, and extends to the roof of the chamber where the deposit of allophane is contained between the two fault faces. In some instances this mineral may be seen adhering to the fault face, and the roof of the denehole is composed of it for a length of about 7 feet by 2 feet wide; other patches are to be observed where the roof has been broken away, so that it seems evident the allophane extends horizontally some distance between the Chalk and the Thanet Sand; this latter is about 32 feet thick here. The deposit appears to be a roughly wedge-shaped mass, the greatest width being at the top of the Chalk, and from there diminishing downwards into tongues of the mineral extending between the two boundaries of the fault. Mr. J. L. Foucar, B.Sc., F.C.S., who kindly submitted a specimen to analysis for me, says: “I find the following to represent its composition:—