32 Praeger — The Estuarine Clays 



of sand above. Shells are far more abundant than in the upper clay, but the 

 number of species much more limited, and they are many of them in a fragile 

 condition. Rare forms which were noticed here are : — Scaphander lignarius, 

 Pleuroioma septangularis, and Eulima bilineata; also Philine scabra, Pecten pusio, 

 and Maetra solida, var. elliptica, which are new to the Clays. At the base the 

 bed becomes very sandy, and Tellina Balthica is abundant, along with quantities 

 of Cardium edule of small size. The lowest zone consists of grey sand, and is 

 quite unfossiliferous. 



5. Immediately underlying the basal sandy layer of the lower clay is the 

 bed of peat before-mentioned, which is now some 27 feet below high water 

 mark, showing a corresponding subsidence of the land. Of course a far greater 

 subsidence, followed by upheaval, has taken place ; for if the upper clay was 

 deposited in 40 feet of water, the total depression must have amounted to 50 or 

 60 feet, followed by 30 or 40 feet of subsequent upheaval. The peat is one to 

 two feet thick, very much compressed, and had originally a much greater depth, 

 as is shown by the flat ellipses into which round branches have been pressed. 

 It is full of trunks and boughs of trees, some of which extend upward into the 

 grey sand. Among the vegetable remains, Willow, Hazel, and Alder are easily 

 recognisable. Hazel nuts occur, and the cones of the Scotch Fir. The broad 

 leaves of the Iris are frequent, with remains of rushes and sedges. But the 

 most interesting fossils which the submerged peat yielded were the bones of 

 large quadrupeds— a tusk and two portions of the jaw of the "Wild Boar, and a 

 rib, vertebra, and leg-bone of the Red Deer. Wing-cases of insects are of not 

 unfrequent occurrence, and in a tolerable state of preservation. In one place a 

 layer of grey sand occurred in the middle of the peat, rapidly thinning out in 

 all directions. A sample of this was kindly examined microscopically by Mr. 

 Joseph Wright, F.G.S., but no organic remains were found. That the vegeta- 

 tion which formed this peat flourished on the spot on which it now rests, and 

 was not drifted thither, is proved by the abundance of fine roots which descend 

 several feet into the underlying deposit, which consists of 



6. Grey sand, some two to three feet deep, very fine on the top, coarser 

 below. In addition to the roots from the peat, of which the sand is full, the 

 only organisms which this bed yielded were Foraminifera and Ostracoda, of 

 which Mr. Wright, who has very kindly examined samples of all the deposits at 

 the Dock for microscopic forms, detected seven species, namely : — Miliolina 

 seminulum, Bulimina pupoides, Lagena laevigata, Rotalia Beccarii, Nonionina 

 depressula, Loxoconcha guttata, Cythere pellucida. 



7. The grey sand merges into fine red glacial sand, a deposit which is 

 largely developed all around Belfast It is very barren in organic remains, the 

 only fossils detected being two Foraminifera and two Ostracoda -. — Polystomella 

 striato -punctata, Rotalia Beccarii, Cythere pellucida, Loxoconcha guttata. 

 This sand, which contains occasional clayey layers, had a thickness of about 

 four feet, and rested on 



8. Very fine tough red clay, of glacial age, the base of which was not 



