402 



PLANER'S LAMPREY. 



Petroimjzon Planer!, Cuvier, Jenyns; Manual, p. 522. 



" " Yarrell; Br. Fishes, vol. ii, p. 607. 



This species bears a near likeness to tlie Silver Lamprey 

 and the Lampern, and on this account there is no doubt it 

 has been overlooked by observers, although the difference when 

 pointed out is sufficient readily to distinguish them. Its peculiar 

 habits have been less noticed than those of others of this 

 family; but having kept alive a couple of them, which had 

 been taken, with many of the Mud Lamprey, in the Trelawny 

 branch of the Looe river, I was able to discern a peculiarity 

 in the manner in which they deal with their prey, after which 

 I suppose them to be not a little eager. After four or five 

 days the smallest of the two was seen to have a wound at the 

 origin of the dorsal fin, and a considerable space of the skin 

 of one side was excoriated; which I felt no doubt to have been 

 done by its companion; and on the eighth day a further injury 

 of the same sort was inflicted; in both cases it appeared to 

 have been done in the night. On the ninth day both were 

 found dead, and both of them bore the same marks of injury, 

 which was widely spread, but little more than skin deep. They 

 did not at any time appear active; at least they were less so 

 than the Silver Lamprey; but when at rest they adhered by 

 the mouth to a fixed substance, which is not usually the case, 

 if ever, with the Mud Lamprey. This species seems widely 

 distributed, as well in Britain as on the continent, except in 

 the more southern portion of the latter. 



Planer's Lamprey is thicker in proportion to its length than 

 the Silver Lamprey; but it is more decisively known from this 

 and the Lampern by the close approach to each other of the 

 dorsal fins; while in the others there is an evident separation 

 between them. It has been called the Fringe-lipped Lamprey, 



