It falls to the lot of only a very few able men to take up some neglected branch of science, and by their genius, their energetic work, the discoveries they make, assisted by their personal charm and bonhomie, to be able to attract general attention to their researches, and so attain a great public success, filling with interest and enthusiasm the intelligent, and attracting even the veriest tyro within the circle of their investigation. Such has been the outcome of the life-work of our friend and associate of many years, Professor John Milne, whose untiring energy in the study of Seismology has obtained for it now a foremost place in the physical sciences as having most important bearings on the economy of the globe and the very existence of our race.

The large collection of specimens of the various species of Trinucleus from British Ordovician beds which is available for study in the Sedgwick Museum offers unsurpassed opportunities for determining the characters of the members of this interesting genus as represented in the British Isles. The following notes have been compiled from a comparative study of this material supplemented by specimens from the Jermyn Street Museum and elsewhere. The frequent addition of specimens to the collection at Cambridge since Salter and McCoy's time have allowed for a more comprehensive and complete survey to be made than was then possible, though several doubtful points still await better material before they can be cleared up.

In addition to the valves from Lüneburg herein mentioned, it has been possible to examine the more important of the material described by previous authors, namely: (1) the valve figured by H. Woodward (1868) as Pyrgoma cretacea, and subsequently (1901) as Brachylepas cretacea, now in the British Museum (Natural History), registered I. 14029; (2) the nearly complete capitulum figured as B. oretacea by H. Woodward (1901), in the collection of Dr. A. W. Rowe, of Margate; (3) the valve figured by Marsson (1880) as Pollicipes cancellatus, together with other valves studied by him, now in the Geologisches Landesmuseum of Berlin; (4) the valve figured by Quenstedt (1883) as P. Iœvissimus, now in the University of Tübingen; (5) the valve mentioned by Boehm(1906), in the Geologisches Landesmuseum of Berlin; and (6) a large number of more or less broken carinæ and rostra, with several scuta and terga, obtained from the Chalk of Rügen by Mrs. Agnes Laur, and acquired by the British Museum (Natural History).

The next step is to see if the evidence of the Echinodermata coincides with and confirms that of the Cephalopoda. The Echinoderms will be tabulated in the same way as the Cephalopoda, beginning with those of Germany. The following table has been compiled from several sources, and may not be quite complete as regards the irregular forms, though it is practically so for the Regulares, this part being taken from Schlüter's monograph on that order:—

From this table it will be seen that there are two different Echinoderm faunas in Germany, just as there are two different Cephalopodan faunas, only two species passing from the lower three to the two highest zones. There is not, however, such a clearly marked line of separation; the fauna of the S. binodosus zone seems from the tabulated species to be linked as closely with the higher as with the lower zones, for it contains sixteen species, of which number ten appear to be restricted to the zone and three range both up and down, while one passes downward only and two range upward. This result, however, is deceptive, because the Emscher is so poor in Echinoderms that only six species have been recorded from it, and only eight have been found in the Marsupites zone.

In the early spring of 1910, while collecting in the Chalk quarry at Borstal, I found in a loose piece of chalk an impression of a small Gasteropod shell which probably belongs to the genus Lampusia. Shortly afterwards, while at the Borstal Manor Quarry, a workman brought me another small Gasteropod, which has since been identified as Turbo geinitzi, Woods. Both specimens were preserved as casts, showing part of the external ornament from near the apex to the basal whorl. Part of the zone of Holaster planus is exposed in the quarry, but the locality is not included in my previous list of exposures in the neighbourhood. The occurrence of these Gasteropods at such an horizon was almost conclusive evidence of the presence of the Reussianum fauna, so I again visited the quarry, in company with my wife, with a view to discovering the exact position at which these fossils occurred.