planer's lamprey. 403 



from a row of tendrils which encompasses the mouth, but this 

 requires explanation. In the Lampern, as we have represented 

 it, there is a border at the same place of very numerous but 

 slender threads; but in our examples of Planer's Lamprey there 

 was only a single row, and each filament was wide at the base, 



ending in a point; the surface red, but of a deeper colour 

 along the middle of the length; and it is remarkable that soon 

 after death these filaments were scarcely or not at all to be 

 discerned. The armature of this species bears a resemblance 

 to that of the Lampern and Silver Lamprey; a row of very 

 small teeth round the lower portion of the entrance of the 

 gullet; two larger teeth above, separate, and another of about 

 equal size outward from each of these; below them on each 

 side a pair, and below them again, nearly on a level with the 

 first-named row, another pair on each side. 



