The Fishes of the Lower Wharfe Basin. 225, 
such as those near Ilkley, at Hollin Hall, and Compton, where: 
it was introduced about seven years ago. 
The Golden Tench, merely a semi-albinoid variety of the: 
Common. Tench, is found in one of the Fewston Reservoirs.. 
where it was placed by Lord Walsingham. 
THE Satmon. The Wharfe cannot be called a Salmon river,. 
as these fish do not exist in sufficient quantities to make it 
worth while angling. At certain times, however, examples may 
be seen rising in the pools at Thorparch and Tadcaster, and 
even ascending the weirs at these places during a heavy run 
of water. It has been reported that Salmon smolts have been 
caught at Ilkley, though this requires verification. Though 
the Salmon is caught on the rod by fly fishing, spinning, or 
with the prawn, it is doubtful whether it feeds in fresh 
water. The stomachs of fish which have been recently killed 
have been carefully examined for traces of food, and in no 
case has any such been found. 
THE River Trout. Seeley asserts that there are ‘ two 
principal forms of the River Trout,’ one distinguished by 
Giinther as Salmo gaimardi, the other Salmo fario var. ausonit, 
by Cuvier. Whether both these forms exist in the Wharfe, 
or merely the one (in all probability the first), is of little con- 
sequence, as the chances of being able to separate the one from 
the other are very remote, owing to the difficulty of ascertaining 
whether the specimens are introduced or genuine natives of 
the streams. As the S. gaimardi is generally considered to 
be characteristic of the northern rivers this variety may be 
taken as typical of Salmo fario, as it certainly was the fish 
described by Linneus. The River Trout is the most valuable 
of the Yorkshire fishes, its sporting qualities and the fact that 
it is at the same time edible, making it the principal game fish 
of the county. The males can be easily distinguished from the 
females by their longer head. Its food consists of flies, larve,. 
worms, and other such substances, and the larger fish will 
take minnow with avidity. The heaviest fish feed almost 
entirely through the night. The size of the Trout varies 
within wide limits, but the examples from typical northern 
streams generally average half a pound in weight. Much 
heavier fish are caught, but these are usually taken from the 
more sluggish and deeper portions of the river, and probably 
are examples of the variety ausoniz, which really belong to- 
the waters of the southernmost portions of Europe and the 
British Isles. 
The Trout of Yorkshire are wanderers, whereas the fish 
of the lower reaches of the southern streams take up their 
position and will remain in their favoured location until the 
approach of the colder weather. In rivers such as the Eden, 
famous for the purity of the water and its association with a 
1913 June tl. 
