406 MUD LAMPREY. 



from the fact that the tide is known to flow at times over a 

 place where they lie hid; and they live longer on the hook at 

 sea than the Silver Lamprey is known to do. 



This fish is widely distributed in Europe, and even in the 

 north; although it has been said that it is not known in Britain 

 north of the Tweed, and it is not noticed by Nillson among 

 the fishes of Scandinavia. But I am informed by Mr. Peach 

 that it is common at Wick. It is classed with the fishes of 

 Hungary by Dr. ileisinger. Its time of shedding spawn is in 

 the spring, and an instance is known of its having done this 

 in captivity. The grains were white, and in size a little less 

 than those of a lobster; but it is probable that they were not 

 fertile. 



The usual length of this species is about six inches, with 

 the circumference of a large goose-quill; but the enlargement 

 is greater along the course of the gill openings. The expansion 

 of the mouth is not circular; but the upper lip is wide, arched 

 into a half circle, and capable of complicated motion; in life 

 well charged with blood-vessels; the lower lip lying across, and 

 it is believed capable of being thrust forward considerably, or 

 rather lifted up, so as with the aid of the sides of the lips to 

 cover the orifice of the gullet. The teeth are not firm, but 

 they exist; a wide border of small ones above, and behind a 

 pair of larger, a pair much larger below. A curious action is 

 seen in life at the place where the passage from the forehead 

 communicates with the gills; and by which it is probable the 

 water for breathing is supplied to the branchiae, as a substitute 

 for the ordinary gill-covers of other fishes. The orifice on the 

 head is far forward. The orifices of the gills are marked with 

 circular lines, each having its own blood-vessel, and which 

 also are discerned at regular intervals along the body; the body 

 itself round until behind the vent, where it is compressed. The 

 eyes are small, and not to be discerned without much attention, 

 situated in a depression, which resembles a channel forward 

 and backward; with a projection above them which serves to 

 guard and also to conceal them. The vent is far behind, 

 opposite an early portion of the second dorsal fin. The first 

 dorsal begins at about the middle of the length, and is narrow; 

 sometimes so much so as scarcely to be discerned; the second 

 a little removed from the first, wider near its beginning, and 



