Natural History. 85 



water mark, presenting clay beds thickly interlaced with roots, 

 also scattered stumps of trees in sltu^ identified as oak, beech, 

 elm, birch, holly, yew, hazel, alder, and willow. The only 

 remains of animal life we have found was during the excavation 

 of the new docks at Grimsby the core of a horn of 'Bos 

 primlgemus. In the peat bed, probably of the same date, which 

 lies below the silt and sand of the Freshney Beck in Aylesby 

 parish, we have dug up bones of the red deer, Bos longlfrons^ 

 wolf, or large dog, wild boar, probably wild cat, and a human 

 ulna^ like the rest stained perfectly black with the peat.* 

 Below the forest bed is the boulder drift, a reddish clay filled with 

 fragments of chalk and derivative rocks, and varying from 50 

 to 300 feet in thickness. A peculiarity of the low-lying 

 districts near the sea, as at Tetney and Great Cotes, are the 

 ponds, locally known as ' blow-wells,' popularly supposed to be 

 unfathomable ; they are powerful springs, never failing in the 

 driest season, rising from the chalk through the superincumbent 

 drift and alluvium. The blow-wells in the parish of Little 

 Cotes supply the town of Grimsby with an unfailing source of 

 pure water. Many of the low-country springs in the north- 

 east districts are more or less intermittent, the flow of water 

 being regulated by the ebb and flow of the tides. Mr. 

 Clement Reid's recent researches in the north of the county, 

 more especially in connection with the old coast line at the 

 base of the wolds, f and the deposits of inter-glacial sands have 

 added much to the geological interest of the district. J The 

 examination of the sand pits at Laceby and Croxton has 

 resulted in the determination of numerous species of marine 

 shells, some yet common on the coast, others slightly northern, 

 but not Arctic, whilst some are indicative of a comparatively 

 warm and equable climate. An interesting find at Croxton is 

 Corblcula fluminalis^ of which living examples are now restricted 

 to the Nile, the Lake of Gennesareth, and some rivers of Asia. 



* The great forest of Kesteven in the south of the county, of which relics 

 remain in Grimsthorpe Park, with its original herd of red deer, probably extended 

 far into Fenland proper. The buried forests beneath the peat comprise oak, elm, 

 birch, Scotch fir, yew, hazel, sallow, alder, and willow. Some of the oaks are of 

 immense size, and the wood, a specimen of which is now before me, nearly as black 

 and hard as ebony. Years after the drainage of the West Fen the exact position of 

 the great trees was made apparent to the fenmen by the rime frost lying longer 

 above them than on the surrounding fen. 



t At this period the coast of Lincolnshire was represented by a chain of low- 

 lying islands of chalk, separated by narrow and deep fiords. 



J ' The Geology of Holderness, and the adjoining parts of Yorkshire and 

 Lincolnshire.' Memoirs of the Geographical Survey, 1885. Clement Reid. 



