The other sponges, from Yucatan and Patagonia, presented by Captain Perry, possess many points of interest; but time does not admit of my detailing them on the present occasion.

Mr. G. H. MORTON, F.G.S., next read the following brief note, "On an Orthoceras, from the Millstone Grit of Sweeney Mountain, near Oswestry," which was also exhibited in the

room :

The large specimen of an Orthoceras, recently added to the Geological collection in the Free Museum, was discovered in the Millstone Grit of Sweeney Mountain, about twelve years ago, by Mr. J. Lester, of Llanymynech, who was engaged in working a quarry in that formation. He carefully worked the specimen out of the rock, and had it set up in the centre of a flower-bed in his garden, on the turnpike road, near Pant, between Oswestry and Llanymynech, about three miles from the spot where it was found.

Just two years ago I happened to pass Mr. Lester's house, and of course recognised the specimen as an Orthoceras, far larger than any I had ever seen, and the final result was, that it was purchased and deposited in the Free Museum.

Although the Orthoceras was exposed to the weather for so many years, it has not suffered any material injury. During this period it was well known in the neighbourhood as a curious fossil, or carved stone, presenting a miniature resemblance to one of the round towers of Ireland.

There is a record of this Orthoceras in an article in the Geol. Mag. for 1865, vol. 2, p. 110-"On the Fossiliferous character of the Millstone Grit at Sweeney, near Oswestry," by Mr. Wm. Prosser. It contains a list of the fossils, including "Orthoceras giganteum (?) Sweeney; very rare." The author remarks that "Savin's Quarry has yielded a splendid speci

men of Orthoceras. In length it was 4 feet 6 inches, and its diameter at the ends 10 and 5 inches respectively."

In 1870, Mr. D. C. Davies, F.G.S., in a paper in the same magazine, on "The Millstone Grit of the North Wales Border," states, that "at Sweeney are found fragments of Orthoceratites; one tolerably perfect specimen measured six feet long, by one foot three inches across its mouth." This description also refers to the specimen under consideration.

Although the specimen is of especial interest on account of its great dimensions, much larger Orthocerata have been recorded. Sowerby* refers to specimens fourteen to twenty feet long, at Closeburn, in Dumfriesshire; but more recent and described examples range from two to three feet in length; and the largest of these, when perfect, must have been about six feet long. A specimen, six feet two inches in actual length, and supposed to have been ten feet when perfect, is mentioned by De Verneuil; it was an American species.

This specimen is now three feet eleven inches long, the width at the summit three-and-a-half inches, and at the base fourteen inches; the apical angle being about twelve degrees. It measures only twelve inches in diameter perpendicular to the line of the original bedding, probably from pressure. There are the casts of twenty chambers above what seems to have been the cavity which contained a portion of the animal, and this final chamber is eighteen inches in length. Originally there must have been, at the least, thirty chambers, and the entire length of the shell was probably nearly six feet, so that it is an exceptionally large specimen.

The siphuncle of the Orthocerata sometimes presents an enormous development, and is subject to such considerable

*Min. Conc.

modification, that generic distinctions have been founded upon it; but in a sandstone cast like the present example, such characters would have been obliterated. Still the position of the siphuncle is visible in the centre of each septum, where the specimen is broken across. About the apex the siphuncle is central, but in the lower septa it is subcentral, probably in consequence of external pressure. The specimen closely agrees with Sowerby's* Orthoceras giganteum, excepting that in his figure the siphuncle is subcentral, and the exterior presents a smaller apical angle than the Sweeney specimen. It is a question whether a slight difference in the position of the siphuncle is of much importance; if it is, the specimen is not Orthoceras giganteum, but a new species of Orthoceras. So far as the apical angle is concerned, it is not of much importance, for it varies in the same species.t

Of equal interest with the size of the specimen is the occurrence of the Orthoceras in the Millstone Grit, for it is the only Cephalopod recorded from the formation, and it is an important species in the comprehensive list of fossils described from the Sweeney Sandstone by Messrs. Prosser and Davies.

The Orthoceras was found in the highest beds of the Millstone Grit, which, however, seem to represent Yoredale strata of other districts.

Dr. CARTER next presented a communication on "The Influence of Anaesthetic Agents on Insect-devouring Plants," which he illustrated by some interesting experiments.

Mr. T. MELLARD READE, F.G.S., exhibited diagrams of Sections of the Boulder Clay at Bootle Lane and the Cliffs of

*Min. Conc.

+ Since this description was in type, Mr. Morton has seen a somewhat larger specimen in the Hunterian Museum of the University of Glasgow; and Dr. Ferd. Roemer, of Breslau, has informed him that he has correctly named the Sweeney specimen as Orthoceras giganteum.

Blackpool, and made observations thereon.

The President

also added some remarks on the Glacial Periods of North

western Europe.

The following Paper was read by Mr. F. P. Marrat, and selections exhibited of the shells referred to :—

"A Brief History of the Collection of Shells of the genus Oliva, or Olives, recently purchased from Mr. F. P. Marrat, by the Committee of the Free Public Library and Museum of Liverpool."

Some ten or twelve years ago, Mr. Reeve, the author of the Conchologia Iconica, sold his collections of shells at the rooms of Mr. Stevens, King Street, Covent Garden, London. At this sale I purchased rather largely, and afterwards found several of the type shells figured in Reeve among my lots; more particularly was this the case in the genus Oliva. Many of the smaller species were separately and securely enclosed in pill-boxes, and named. At this time I knew very little of the shells comprising this extensive genus. The smaller Cypræa (Trivia) accompanying these were many of them belonging to species rare and difficult to procure; and I thought such might also be the case with the Olives, therefore I put them in safe keeping for some future time.

M. Rubilliard sent an extensive collection of shells to the same rooms, some five or six years after Reeve's sale mentioned above, and amongst these were ten lots of Olives, the finest series I had then seen; and even now they stand boldly out as prominent shells in the collection. I debated the point with myself, whether I should secure the whole, or allow them to be scattered broadcast. The result was that, after some spirited bidding, the whole of the lots were mine. I have since learned that M. Rubilliard had selected these shells from thousands of specimens caught in the neighbourhood of the Mauritius.

The method of fishing for these and similar molluscs was

e

related to me by Sir David Barclay, Bart., a gentleman who has often been engaged in this work, and who is well acquainted with M. Rubilliard. A line, with three or four strings attached, is baited with pieces of fish-one of the principal of these is the cat-fish-and thrown into the sea, where it is allowed to remain sufficiently long for the molluscs to settle down to their feast. When the line is hauled in they will be found to stick fast to the bait. A similar operation may be seen on our pier-head, when boys are fishing for crabs.

The impulse given by my obtaining the splendid shells mentioned above induced me to purchase largely, not only with a view of acquiring the shells similar to those figured as species, but also any varieties that might be found to differ from the type forms. After several years' careful study, the fame of my collection became widely spread, and I received specimens from various collectors in Europe, who were anxious to have their shells named correctly. In most cases they gave me the privilege of selecting from specimens

so sent.

Many beautiful varieties were obtained by friends dredging on the West Coast of Africa, commencing at Madeira, and continuing these operations, as opportunities offered, all along the coast as far as Corisco Bay.

Either by purchase or otherwise the finest shells, selected from almost every lot imported, found their way into my drawers, until it required at least twenty to hold them.

Every visit to London enabled me to add to the stock some little. Either shells have come in excelling in size or quality anything previously collected, or some hitherto unknown beautiful variety was selected by the experienced eye from among a hundred others.

Correct localities have been obtained through the instrumentality of masters of vessels of our mercantile marine,