As Carnegie Research Scholar in Geology under Professor James Geikie, D.C.L., LL.D., F.R.S., at Edinburgh University, I have entered upon a systematic examination of fossil plants from Pettycur, Fife. Though many plants have been described from this locality, nothing systematic, as far as I know, has ever before been attempted. The main objects of this research are to endeavour to connect the various strobili obtained at the locality in question with the stems on which they were borne; to describe any new species met with, and to give some account of the mode of occurrence of the material in which the plants are enclosed. Some of these objects have already been attained, but others will require further study to decide.

In the first part of the present series of communications I have given a general discussion of the apparatus and methods of observation employed in the investigation of the seiches of Loch Earn, and have also mentioned some of the errors to which seiche observations are liable, and how they may be avoided or corrected. It may be useful to enumerate here certain of these errors, omitting for the most part those that arise from the construction of the instruments, and can be eliminated by proper design and by preliminary tests.

Having had the privilege of examining the type specimens of Turrilepas scotica, Etheridge jun., and T. Peachi, Etheridge jun. and Nicholson, in Mrs Gray's collection, and in addition to them a large number of examples of the genus recently collected by Mrs Gray from the Girvan area, as well as many specimens in the Sedgwick Museum, Cambridge, from several horizons in the Haverfordwest district and from the Dufton Shales near Melmerby and from Bala beds of other localities, some important new features have been recognised in these curious fossils which help to throw light on their structure and relations.

La collection d'Astéries, d'Ophiures et d'Échinides, dont M. le Dr. William S. Bruce a bien voulu me confier l'étude, comprend surtout les échantillons recueillis par l'Expédition de la Scotia lors de son séjour dans l'Antarctique et quelques autres provenant des îles Falkland, du banc de Burdwood et de l'île Gough, ou de dragages effectués entre le 46° et le 51° lat. S. M. Bruce y a joint quelques spécimens capturés pendant le voyage de retour de la Scotia, au Cap, à Sainte-Hélène, à l'Ascension et à Saint-Vincent.

We have already referred in the second part of this series to the opinions held by various authors as to the systematic position of the genera Thamnopteris, Bathypteris and Anomorrhœa, and have given in detail the reasons that have induced us to adopt these names for the specimens included in these genera (cf. Part II., p. 213). It is therefore unnecessary for us to deal any further with the historical aspect of the matter in the present communication, and we will at once proceed to the description of the structure of the Fern stems in question.

The first and second parts of this work (7, 8), on the skeleton and muscles respectively, were published in the Transactions of the Society for 1905 and 1907. The third part would naturally have related to the viscera, and this, in fact, is in active preparation, but it is first necessary to amplify the description of the skeleton. Figs. 1 and 2 in my first part were based on dissections, which were executed very carefully, and the results checked by the examination of serial sections. It is, however, peculiarly difficult, and especially so in Myxine, to preserve the natural relations of the parts, and these drawings therefore exhibit the defects incidental to the method by which they were prepared. I mean by this, not that they are inaccurate, but that the interrelationships of the parts could not be faithfully represented. Quite apart from this, however, it became necessary to re-draw these figures.