poured off the water holding the lighter particles in suspension, allowed the remainder to rest for a time, when the clear supernatant liquid was removed and the residue dried and afterwards ignited for half an hour, which dissipated the organic substances present; boiled in strong hydrochloric acid, thus dissolving the alumina, iron, and lime, and leaving a white powder composed exclusively of diatoms and grains of quartz. These were separated to some degree by repeated washings, the heavier fragments of quartz subsiding rapidly and remaining behind. In submitting a list of the species of organic remains, I may premise that a few of the names must, from the fragmentary state of the objects, be held only as indicating their possible affinities. PLANTE. DESMIDIEE.-Micrasterias denticulata, in the sporangial state. Abundant. Staurastrum polymorphum. A single example. Cosmarium. An empty frond. PHANEROGAMIA.-Ranunculus aquatilis, Galium palustre, Pedicularis palustris. Many seeds of these plants were found, chiefly in the upper bed. This is the commonest form in the deposit, composing probably a fourth of the whole. 2 This moss belongs to the subgenus Webera of Schimper. Texture and serratures same as W. nutans, but leaves somewhat broader. Myriophyllum spicatum. Represented by a portion of the character istic leaf. Scirpus lacustris. In the upper bed only, where it was very abundant. Potamogeton lucens. Leaves and seeds frequent. Scutellaria galericulata. A leaf of an herbaceous plant most closely agrees with this species. Betula alba. Numerous twigs of this tree were found in the lower bed, none in the upper. Corylus Avellana. Represented by a fragment of root-also from the lower bed. ANIMALIA. Numerous objects were found which seemed to be the remains of infusorial life but too incomplete for identification. SPONGIDE.-Spongilla fluviatilis. The acicular spicule of a freshwater sponge were very frequently to be met with,-occurring indeed on every slide. In one instance I got a fragment of the sponge itself, with the contained spicules, which quite agree with those of S. fluviatilis. ANNELIDA.—Hæmopis sanguisorba. Two examples of the jaws of this leech with teeth all perfect. CRUSTACEA.-Daphnia ? There occurred a very complete organism, with rudimentary eyes and jointed limbs, which I consider to be a larval form of Daphnia. The lower bed contains thousands of fragments of clear yellowish animal tissue which, from its markings and other characters, I think are the remains of a soft-shelled Entomostracan. INSECTA. Portions of the elytra of beetles were pretty frequent. Many mandibles, etc., have been mounted by Mr. J. Coutts-the various objects indicating the presence of at least three species. MAMMALIA. Bos primigenius. A skull exhumed by the labourers and described by Mr. James Geikie. The evidence presented to us by these stratified beds clearly suggests the existence of a lake, and the organisms that peopled its waters, or lived along its margin, have been here wonderfully preserved during a long lapse of time. The extent of this time it is difficult to determine (although the latest observations on the section tend to confirm the opinion of these beds being of Boulder-clay age), but that it dates at least from the close of the Glacial period is well shown from the following circumstance. The porphyritic trap, which rises as a sloping wall at the lower end of the beds and forms their eastern boundary, is a rock easily acted on by the weather, and already, after two years exposure consequent on the removal of the clay, exhibits much disintegration. Now this rock face is highly glaciated, presenting a polished surface with deep groovings and striations which have evidently been protected from obliteration by the water of the small lake, formed soon after the disappearance of the ice, and afterwards by the beds of clay and sand deposited as the lake gradually silted up. Had the |