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thick. The surface layer is sandy, -with great abundance of Littorina litorea. Below, it is fine and tough, and yields an abundant and interesting fauna, chiefly remarkable for the variety of shells of the Limpet section which occur, no less than five genera being represented—Patella, Hclcion, Tectura, Emarginula, and Fissurella—all of which, as would be expected, are very sparingly distributed in the estuarine clays. Gastrana fragilis is an interesting Bpecies with a southern distribution, not now occurring in the north-east—one valve in the clay here, and another at Downpatrick show that it formerly inhabited Strangford Lough. The more abundant shells of the deposit give a rather mixed fauna as regards depth—Lucina borealis, Tapes aureus, Cardium exiguum, Fissurella gresca, Lacuna pallidula, Littorina litorea, Hydrobia u/ra, &c. Foraminifera are very raro in the clay at this station.
(13). Downpatrick.—One would hardly suspect that the extensive marshes which stretch around this ancient town covered a deep deposit of marine clays. Surrounded by hummocky hills, through which the River Quoile follows a narrow and tortuous course for several miles, till it joins the waters of Strangford Lough, these marshes more resemble the silted-up bed of a former lake than an old 8ea bed. The latter, however, is the case, and until the flood-gates, a mile below the town, were constructed in 1745, the marshes were slob lands covered at each tide. Piles driven in the construction of the railway bridge over the Quoile were sunk forty feet without reaching a solid bottom, and the excavations for the turntable at Downpatrick railway station, though almost on the limit of the swamp, were made through thirty feet of estuarine deposits. The surface here is about high-water mark; in the basal portion of the excavations quantities of oyster and mussel shells occurred, and below them was a bed of peat, with hazel nuts and fir cones. So that we have here upper and lower estuarine clay and submerged peat in the usual succession. That the greater depth of the clay belongs to the upper zone is shown by its fauna—Turritella terebra, Nassa pyjmtea, Nucula nucleus, Lucina borealis, Axinus fiexuosus, Cardium txiguum, Scrobicularia alba occurring plentifully in the deposit. The clay contains much vegetable matter, and many of the shells are of dwarf size. The abundance of long tubes of Serpula vermicularis is remarkable: Foraminifera are plentiful, the genera Miliolina and Bulimina being especially well represented. The turntable mentioned was constructed some years ago; but information kindly supplied to mc by Mr. F>. D. "Wise, M. Jjtst. C.e., then engineer of the railway, and an examination of the material from the excavations, which was happily still available, enable me to describe the bed, and catalogue it* fossils.
VI. DuKDBCM BiY.
Estuarine deposits might be expected on the shores of the sheltered Inner Bay of Dundrum, but hard sand only appears to prevail there. The outer bay is very open and exposed, with extensive sandy beaches.
(14). Netccattle.—At Newcastle, situated at the southern extremity of tho outer bay, I was surprised to discover a bed of typical Scrobicularia clay. It occurs on the beach near low-water mark, a short distance north of the harbour, covered by an inch or two of sand, and was detected by the washed-out valves of Scrobicularia piperata on the shore in its vicinity. The clay is very pure, fine, and tough, crammed with Scrobicularia and Zostcra roots: Cardium edule, C. exiguun, Tellina balthica, Scrobicularia alba, Pholai Candida, Littorina rudit, L. litoria, Hydrobia ulvat, Skenea planorbit, Cerithium reticulatum, and Utriculus mammillatui, complete the list of fossils—most of them occurring very sparingly. Foraminifera are rare; the deposit is of small extent; it is at least four feet thick ; the lower portion becomes sandy, with greater abundance of Scrobicularia. Several mountain streams discharge into the bay at no great distance, and had probably something to do with the formation of this deposit, but the surroundings when it was laid down must have differed from the present shallow, sandy, storm-swept bay.
In a Paper read before the Belfast Natural History Society on February 24th, 1858, Dr. Dickie described a "recent deposit of wood, shells, &c, discovered by Dr. Kea at Newcastle, county Down. This deposit is Post-tertiary: it contains leaves and pieces of wood, oak, beech, and Scotch fir, also a number of Scotch fir cones. The shells belong to species chiefly littoral, but still existing on the neighbouring shores. They are Scrobicularia piperata, Cardium edule, Tellina tolidula, Littorina litorea, Rittoa ulvce, Patella vulgata, Troehus umbiUcatut." This description would correspond closely to the bed which I have described, with an underlying zone of submerged peat such as might be expected, but remains of the beech should not occur in any undisturbed Irish geological deposit, as that tree is a recent introduction to Ireland.
At Killough, on the county Down shore, north of Dundrum Bay, a narrow estuarine flat extends inland from the sea for about a mile, ita surface slightly above high-water mark. Below a foot of sandy clay is a shell layer, full of Scrohicularia piper at a, Cardium edule, Tellina balthica, and Littorina litorea. It rests on gray and pink fine laminated clays, apparently of fresh-water origin. In the muddy bay adjoining, I searched in vain for Scrohicularia, which has quite deserted its former haunt here, as elsewhere.
The Carlingford Lough estuarine clays may be seen close to Greenore. Similar deposits might be expected at Mill Bay, on the northern side of the lough, hut sand only is seen there; and the low land that lies along the river from Narrow-water to Newry has probably a subsoil of estuarine clay, but no sections of sufficient depth are available.
(15). Greenore.—On the shore, at the railway junction between Carlingford and Greenore, the weight of the embankment has forced up the estuarine clay some five feet above its natural level, which is here two feet below high-water mark. The clay is rather sandy, and resembles the Newcastle bed, in containing Zostera and a profusion of a few littoral species, intermixed with shells pertaining to the five-fathom clay. Ostrea, Anomia, Pecten varius, Tapes decussatus, Trochus einerareus, Rittoa membranacea, Littorina litorea, Turritella tertbra are in abundance. Pecten opercularis, P. maximus, Cardium exiguum, Scrohicularia alba also occur, mixed with species which flourish between tides. Foraminifera occur but sparingly. The clay is at least five feet thick, and its base is not seen. Southward, it runs in under the raised beach at Greenore, and underlies gravels some fifteen feet in thickness, which, from base to top, contain shells similar to those of the clay.
The bay is fringed with a wide and dreary extent of slob-land, which extends far out into the water. No sections were exposed; but it is possible that the beds are of considerable depth.
(16). Dundalk.—At Soldier's Point, at the entrance to Dundalk Harbour, the raised beach, resembling that at Greenore, rising some 15 feet above high water, and containing shells, overlies deposits of the estuarine clay series. Seaward of the gravels, the estuarine deposits extend, their surface a few feet above high-water mark. Small streams have cut through them to a depth of eight or ten feet, revealing horizontal beds of brownish littoral clay and gravel. The shells obtained are our commonest littoral species, and but little interest attaches to the deposit.
Deposits of the estuarine clay series probably occur at many points on the Irish coasts. The foregoing enumeration shows that they are to be found at almost every suitable locality in the district dealt with; and, although there are few records of their occurrence elsewhere in Ireland, there is no reason to suppose that they are almost from any part of the seaboard. A thorough knowledge of these deposits would probably throw much light on local later Post-tertiary geology. The Memoirs of the Geological Survey and other works contain mention of the submerged peat zone, but the estuarine clays, which probably in many cases overlie them, do not appear to have been considered worthy of notice. A bed of undoubted estuarine clay occurs at Clontarf, near Dublin, and has been mentioned by several writers. Turton1 appears to have first noticed it, and records from it Gastrana fragilit, and also two varities of Tapes aureus (as Venus centa and V. nit-ens). Thompson writes,1 under Petricola ochroleuca (Gasirana fragilis)—"Not uncommon in a deposit of blue clay in Dublin Bay, where it was found many years ngo by Mr. Furlong (O'Kelly, in Penn. Brit. Zool.). In 1840, I procured it there from the same material brought up from a depth of several feet." This bed is also mentioned in Canon Grainger's Paper, which author states that Serobicularia piperata occurs in it abundantly. This deposit would be well worth working out. The occurrence of Gastrana fragilis is interesting, as the only other record of its occurrence on the east coast of Ireland is also from estuarine clays, in Strangford Lough, as cited in the present Paper.
In the annotated and tabular lists which follow, all records are on the authority of the writer except when otherwise stated. In both lists, species which have been recorded by other observers, but did not occur to the writer at any of the stations examined by him, are distinguished by the prefix of an asterisk. In the annotated list, any recorded stations for a species, which are additional to those at which it was observed by the writer, are mentioned.
I must hero return my best thanks to those gentlemen who rendered me kind assistance in the preparation of the present Report. My thanks are especially due to Mr. Joseph Wright, F.o.s., of Belfast, who,
1 " Conehological Dictionary of the British Islands."
Lb already stated, prepared the list of Foraminifera found in the leposits, a work involving much labour; to Mr. J. T. Marshall, of Torquay, who revised all my Rissose and Odostomise, and gave his "aluable opinion on such other shells as were critical or doubtful; to Dr. R. F. Scharff, of Dublin, who went through the land-shells; and :o Mr. S. A. Stewart, of Belfast, who gave me the benefit of his long sxperience and critical judgment in a number of ways.
ANNOTATED LIST OF SPECIES.
The Foraminifera found in the clays number 114 species. These are all shallow-water forms, and do not need to be separately dealt with. A tabulated list is given on a subsequent page showing their distribution in the various deposits.
Echinut miliaris, Leske. Spines and fragments of tests of this urchin occurred in most of the deposits ; they were noted from the Lough Foyle and Belfast Lough beds, Magheramorne, Newtownards, Downpatrick, Newcastle, and Greenore. Stewart noticed closely packed layers in the clay at Spencer Basin; the same occurred to me at Alexandra Dock.
E. sphctra, Miiller. Fragments of large tests at Alexandra Dock and Magheramorne.
Amphidottu cordatus, Pennant. Of frequent occurrence in the Belfast bed, as at Spencer Basin (Stewart), Alexandra Dock, "West Bank \ and in a fragmentary state, very rare, at Limavady Junction.
*P«eiinaria belgica, Pall. Recorded by Grainger from the Belfast bed. Sfrpula iriquetra, Linn. Frequent on shells in the clay at Belfast,
Magheramorne, and elsewhere. S. ttrmicularis, Linn. Rare at Belfast; abundant in the Downpatrick
Spirorbu communis, Fleming. On shells at Belfast, Larne, Magheramorne, Downpatrick, and Eglinton. At least one other Spirorbis occurs, but I had no opportunity of determining the species.