MUD I.AMPREY. 
407 
then narrower where joined to the caudal fin, which passes 
round the body and forward half way to the vent. The colour 
dark yellow on the back, with sometimes a tinge of green; 
yellowish below, and on the fins. The openings of the gills, 
which arc in a sunken channel, and sometimes the lower portion 
of the body opposite them are often a lively pink. 
An irregular formation has occurred in this fish, in the 
division of the body into two separate portions from the part 
just above the vent backward. Both of these portions were 
bent down from a straight line, and one of them was a little 
longer than the other, and more active, but the other w'as 
more in the right line of the vertebral direction. The shortest 
was also a little irregular in shape, and bent at the caudal 
extremity. A faintly-marked first dorsal fin lay a little before 
the separation of the vertebrje into two columns, and the 
second dorsal is turned round in a circle at the place wheie 
the portions of the body divide, as if this fin was directed 
down one of the parts and up the other. These two parts of 
one body diverged to some considerable extent. The fish was 
about half the usual size, and active. 
It should be observed that the eyes ot the Mud Lamprey 
can be noticed only when the fish is alive, as presently after 
death they are scarcely or not at all to be discerned. The 
teeth also, as being of a soft or cartilaginous substance, can 
be made out only during life. 
