Xxiv YORKSHIRE—PHYSICAL ASPECT. 
is one of the most diversified possessed by any English county. 
The estuary of the Tees—though by no means comparable in 
size or attractiveness to that of the Humber—is yet of considerable 
extent. It includes vast stretches of sands, which afforded the 
last breeding haunt of the seal in Yorkshire (one sandbank 
indeed bearing the name of ‘Seal Sand’); also a series of low 
salt marshes bordered by sandhills, and intersected by pools and 
saltwater ditches—formerly the habitat of shore fishes, and an 
attractive resort for such migratory birds as the waders, ducks and 
geese. But, as so often has happened in the north of England, 
the development of trade has here sadly interfered with the 
natural productiveness of the district. The discovery of Cleve- 
land ironstone—and consequent rapid rise of Middlesborough as 
a manufacturing and sea-port town—has involved a train of con- 
sequences which have done much to render the zoological riches 
of the Tees mouth almost a tale of the past. The ‘navigation 
has been improved, foreshores embanked and reclaimed, docks 
and harbours built, breakwaters projected, and blast furnaces 
erected along the Coatham Marsh. 
One of these furnaces, built within five hundred yards of the 
site of a decoy, caused—and no wonder—its discontinuance, 
about 1872. Formerly this decoy was fairly productive, and on 
one occasion yielded a haul estimated at five hundred. At any 
rate, so great was the number enclosed in the net, that it broke, 
and most of the ducks escaped, only ninety and nine being 
actually secured. Ducks are now but seldom seen on the Coatham 
Marsh, though the sheldrake nested on the sandhills as late as 
the year 1880, and may still continue to do so. 
The Coatham Marshes and the adjoining Redcar coast possess 
an interest to the ichthyologist as the scene of the labours of 
Rudd and Ferguson, two of the most energetic observers that 
have worked at the fishes of the Yorkshire coast, and the results 
of whose researches are summarised in the lists appended to 
‘The Natural History of Redcar.’ Many rare fishes have here 
been noted, including Ray’s sea-bream (of which the first 
recorded or known specimen occurred here exactly 200 years ago, 
and was described by Ray and Willughby), the argentine or 
pearlside, the blackfish, and the Hebridal argentine. 

