392 SEA LAMPREY. 



only by a lighter sand. A stone of the weight of two pounds 

 has been known to be thus carried to a sufficient distance; 

 and Mr. Thompson reports on the authority of a fisherman that 

 stones of even ten or twelve pounds have been turned over, 

 ''^oon after spawning the parent fish return to the sea. 



As the manner in which the water is received by this fish 

 for the purpose of breathing, has been described in a way that 

 is contrary to my observations, the folloAving notes are given 

 from my own examination of the subject; derived chiefly from 

 a large example taken in the sea: — When this fish was altogether 

 immersed in the water, the fluid was seen to enter by the orifice 

 on the head, and was discharged through the branchial orifices 

 at the sides. When these orifices on one of the sides were 

 put of the water it was still discharged through both, but with 

 less force; but when the aperture on the head and the branchial 

 orifices on one side were equally out of the water, although 

 the fluid ran out for a short time, as if what had been adhering 

 to the gills within supplied it; yet afterwards it ceased with 

 something of a sucking motion, as if the gills were drawing 

 without being supplied. But on a further trial with the same 

 fish, when the whole body was immersed in the water, a constant 

 current was discharged from, not inhaled by, the aperture on 

 the head, in common with the gills; but when the head was 

 lifted above the water, and all besides immersed, the current 

 ceased from the head, although it continued from the gills. 

 When the mouth was lifted from the water, and the aperture 

 on the head was immersed, no water entered by the latter, 

 although the current ceased from the gills: a circumstance not 

 easily explained, except on the supposition that the powers of 

 life, usually of an enduring kind, were about to cease. 



This fish inhabits climates between the very warm and very 

 cold; it is therefore found in the Mediterranean; and also in 

 the north of Europe; where it is mentioned by Nilsson as 

 common in the Baltic and North Seas; but it is not mentioned 

 by Fabricius in Greenland. 



The example described was obtained from the Severn, and 

 measured two feet eight inches in length, and six inches and 

 a half round the body where stoutest; which was at the last 

 spiracle; round anteriorly, more compressed towards the tail; 

 rather flat on the head, and when the mouth is closed bluntly 



