THE RIVER LAMPREY. 445 



wards ; between and a little in front of the eyes, is a small aperture 

 through which the water escapes. Dorsal fins two, distinctly sepa- 

 rate, somewhat of a triangular form, the first considerably smaller 

 than the second, and situated about mid-way between the tip of the tail 

 and the third branchial opening ; the height about one-sixth the length 

 of the base. Second dorsal commencing at a short distance from the 

 termination of the first, beginning at first low and attaining its great- 

 est height rather suddenly, from thence gradually sloping off and 

 uniting with the caudal : pectorals and ventrals wanting; caudal cut 

 obliquely above and below, terminating in a point ; skin perfectly 

 smooth. Colour above of a dusky blue, beneath silvery white. 



. This species of Lamprey is met with in much greater 

 numbers in some of the rivers in England, such as the 

 Thames, the Severn, and Dee, than in any of the rivers 

 either in Ireland or Scotland. It was formerly a fish of con- 

 siderable importance. " Itwas taken in great quantities in the 

 Thames from Battersea Reach to Taplow Mills, and was sold 

 to the Dutch as bait for the turbot, cod, and other fisheries. 

 Four hundred thousand have been sold in one season for 

 this purpose, at the rate of forty shillings per thousand. 

 From five pounds to eight pounds the thousand have been 

 given ; but a comparative scarcity of late years, and conse- 

 quent increase in price, has obliged the line fishermen to 

 adopt other substances for bait. Formerly the Thames 

 alone supplied from one million to twelve thousand Lam- 

 perns annually.'""* These fish are frequently observed in 

 some of the larger rivers entering the Firth of Forth, and 

 specimens are occasionally seen in the Firth itself; but as 

 the fishermen place no value on them either as bait or for 

 food, they remain totally disregarded. Some authors sup- 

 pose, that the River Lamprey is a migratory species, as- 

 cending the rivers in spring and returning again to the sea 

 after spawning; but Mr Yarrell is induced to believe that 



" Yarrell's British Fishes. 



