Appendix 2 Statistics of fossils, rock-specimens and slides, chemical analyses, and photographs

Fossils

Nearly all the fossils quoted are in the collection of the Geological Survey, and are referred to by their registered numbers, thus '[Af. ]'. Of the 4,580 Anglesey fossils in that collection, 2,390 were collected by Messrs. Macconochie and Muir, with several weeks' assistance from Mr. J. O. Hughes; and the remaining 2,190 by the author, also with some assistance from Mr. Hughes. Mr. Thomas Prichard, of Llwydiarth Esgob, lent 53 Coal Measure plants; and quotations are also made from some other collections, chiefly those of Dr. Matley and the Sedgwick Museum at Cambridge. All the fossils have been named by specialists, as explained in the Preface. The localities given in this memoir are from the one-inch map. More precise localities will be found upon the manuscript copies (p. 921) of the six-inch maps preserved in the offices of the Geological Survey.

The type-specimen of Glyptograptus serrates var. barbatus E.&W. (p. 481–2) [one of the series Af. 277–98] is in the Survey collection; but the Parys Mountain fossils have unfortunately proved very difficult to preserve, as their disseminated sulphides oxidise and give rise to efflorescent sulphates. The type-specimen of Productus [Daviesiella] conmoides J. Sow. (p. 645) is in the British Museum [Reg. No. 43390]. Chonetes sp. [C. compressa Sibly non Waag.] of the lists is the form for which Dr. Ivor Thomas (p. 612) proposes the name C. siblyi. Campophyllum sp. nov. of the lists is the C. derbiense Vaughan MS. of p. 612. The specimen of Cephalograptus cometa Gein. mentioned on p. 482 is in the collection of Mr. Griffith J. Williams.

Rocks and microscopic sections

The rocks and slides in the collection of the Geological Survey are referred to by their registered numbers, thus:(E   )<ref>The quotation '[AP.]' refers to specimens that have been examined in powder.</ref> The Survey collection contains 1,800 sliced rocks from Anglesey, which have been acquired as follows: Cut by Geological Survey (nearly all of them kindly made for the present work) 345; Blake and Callaway collections purchased, 320 and 161 respectively; presented by G. Barrow, C. A. Matley, and E. Greenly, 3,160 and 811 respectively. Registered numbers have been attached to all, however acquired. Some slides from other collections (chiefly those of Prof. Bonney and Miss Raisin, and the Sedgwick Museum at Cambridge) are also quoted. The localities given in this memoir (save in the cases of some analysed specimens, and those which come within the (Folding-Plate 13), (Folding-Plate 14), (Folding-Plate 15), when six-inch map localities are given) are taken from the one-inch map. On the labels attached to the slides and specimens themselves, however, more precise localities, taken from the six-inch (occasionally from the .0004) maps are given; except upon those of the Blake and Callaway collections and some older specimens in that of the Survey, which are localised from the old one-inch maps only. Most of the unsliced Anglesey rocks collected by the author have also been handed over to the Geological Survey.

Chemical analyses

Analyses of 138 Anglesey rocks and minerals are given, 93 of which were made for this work. Mr. J. Owen Hughes made 81, of which 45 are complete and 23 partial, and 13 qualitative. All his quantitative determinations, as here published, are means of duplicates. We are also permitted to give 33 quantitative analyses, not previously published, by other chemists, 18 of which are complete and 15 partial; 12 of them having been kindly made for this work. We also quote 24 complete quantitative analyses which have appeared in previous publications. A number of soil-analyses (which are partly chemical) are also quoted.

Photographs

The Survey collection of geological photographs now contains 203 views of Anglesey geology, taken in the field, 61 of which are reproduced as plates in this memoir. Those taken specially for the Geological Survey, 181 in number, are by Mr. John Rhodes, Junior; but two have been presented by Mr. E. Neil Baynes, 10 by Mr. J. Trevor Owen, nine by Mr. H. E. Spencer, and one by Mr. Griffith J. Williams. Besides these, 64 microphotographs of Anglesey rock-slides have been taken, 40 of which are reproduced by collotype in this book.

Prints may be seen at the offices of the Geological Survey (28, Jermyn Street, London, S.W.1; and 33, George Square, Edinburgh), where catalogues or subject-indexes can be consulted. From either of these offices a leaflet can be obtained, giving full information as to the prices at which prints, lantern-slides, or negatives, whether of the field- or of the micro-photographs, can be purchased.