JltTD LAMPREY. 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 was 

 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 vertebras into two columns, and the 

 second dorsal is turned round in a circle at the place where 

 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 of 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. 



