In a recent paper on the Wenlock and Ludlow rocks of the district around Gwytherin, North-Western Denbighshire, Professor Boswell deals with an area which lies to the south of the Llangerniew district that I mapped and described a few years ago.

The International Rules of Zoological Nomenclature aim at the “elimination of all possibilities of discussion”; and in troubled times like the present, when it is impossible to secure decision on a knotty problem by the International Commission, automatic solution of any nomenclatorial difficulty should be particularly welcome. We all know of certain genera that have caused trouble to revisers because they were based on several species, subsequently found to belong to more than one genus; likewise species have often been based on a number of differing specimens, some of which have in course of time been relegated to other species or genera. Now Opinion 88 claims that the procedure to be followed in such cases is well known, but on this point there appears to be some doubt, and I therefore propose to discuss the two species mentioned in the above title1.

Attention has recently been directed, particularly by the writings of Boswell (1942) and Smithson (1941, 1942), to the instability of detrital minerals. In nearly all cases where etching of mineral grains has been described the rocks have been deposited under water, as members of a continuously sedimentary series.

The Whidborne Collection of Devonian fossils from Devon and Cornwall now in the Sedgwick Museum, Cambridge, contains the majority of the specimens and nearly all the types described and figured by him in his memoir published by the Palaeontographical Society, vols. xlii-lii, between the years 1889–1898. The following notes have been made on a re-examination of certain of his Upper Devonian specimens in the light of more recent work and other material, though unfortunately many of the fossils are too imperfectly preserved for a satisfactory determination. A comparison of several of the species with those of Sowerby's types described and figured in 1840 has been of much value. Those specimens in the Whidborne collection which require no further remarks or are so poor that a correct identification is deemed at present impossible are omitted.