THYMALLUS VULGAEIS. 855 



just ready to deposit the eggs. A thread is tied firmly to the dorsal fin of the 

 fish, and fixed at the other end to a small stake driven in the bottom of the 

 brook. A net is then placed on the bottom, and as soon as the males come 

 near the net is quickly raised. 



The Grayling is not recorded from Ireland, has only recently been in- 

 troduced into Scotland, and is most abundant in the limestone country of the 

 Pennine chain, in the Chalk streams of the South of England, and Triassic sands 

 of the Central districts. The Severn, Dee, Trent and its tributaries, and the 

 tributaries of the Yorkshire Ouse, are all favourite Grayling waters. Pennant 

 says the largest fish he ever heard of, taken near Ludlovv in the Wye, was above 

 half a yard long and weighed four pounds, six ounces. But from time to 

 time specimens only a little inferior to this in size are taken in the South of 

 England. Specimens weighing four pounds have been got in Denmark, and 

 a weight of five pounds is recorded in Northern Scandinavia. The Gray- 

 ling is found also in Lapland, where the gastric juice is said to be used in 

 making cheese from the milk of the reindeer. In France and Germany it 

 measures from a foot to fifteen inches. It occurs only in the East of France, 

 the Lake of Geneva, the Auvergne, and some tributaries of the Rhone. In 

 Switzerland it is characteristic of Lake Constance and the other lakes. It 

 occurs in the mountain lakes of Austria, Hungary, and Transylvania, and their 

 tributary streams, where it is sometimes two feet long, though commonly a 

 foot and a half. It is found in Lombardy, Piedmont, Venice, and Istria. In 

 Russia it is confined to the small rivers, and upper parts of the large rivers which 

 flow into the Arctic Ocean, White Sea, Baltic, Black Sea, and Caspian. 



The shape of the Grayling is eminently elegant ; the body is five times 

 as long as high, and six times as long as the head, though in some indi- 

 viduals the head may be a little larger/ and the body a little higher. The 

 body is twice as high as thick, but the head is only one-third higher than 

 broad. The eyes are as far from each other as from the snout. Their diameter, 

 including the adipose margin, is one-quarter of the length of the head. The 

 dorsal profile is more arched than the ventral outline, and the convexity is more 

 developed in the front of the body than in the genus Coregonus. The double 

 nares are nearer to the eye than to the snout, which is blunt and somewhat 

 broad, and projects a little over the lower jaw, so that the aspect of the mouth 

 is inferior. 



The pre-maxillary and maxillary bones are small, the latter extends back as 

 far as the anterior margin of the pupil ; though the mouth is small. The 

 delicate teeth are largest in the pre-maxillary bone ; they form a simple row in 

 the maxillary bone, but are in groups on the vomer and palatine bones. The 

 termination of the tongue is a round free point. The gill-openings are very 



