Thomson. — On a New rantaitic Copcpod. 229 



outer margin, and 5 plumose setffi — increcising in Icngtli in- 

 Avards — at the extremity. 



The legs of tlie third riair (tig. 10) are 2-branched, and 

 «ach branch is 3-jointed. Basal plate very large and -wide, 

 and ha\-ing a strong spine just above the insertion of the very 

 small branches. Outer brancli having 5 or 6 short setai at 

 the end of the rounded terminal joint. Inner branch Avith a 

 long plumose seta on the inner side of the 1st joint, and G 

 plumose setae on the outer joint. 



The legs of the fourth pair are very long and slender, and 

 1-branched, with the basal joint slightly dilated. Branch 

 3-jointed : 1st and 2nd^ joints oblique at the ends, and each 

 bearing a small spine on the outer extremity ; terminal joint 

 Avith 3 slender spines, inner mucli the longest, outer the 

 shortest. 



This is a very small species — not more than one-fourth the 

 length of L. huttoni. It is just possible that it belongs rather 

 to Heller's genus Amiretes than to Lepeophthcirus ; but in 

 the absence of the complete literature of the subject I cannot 

 be certain of this. The structure of the limbs is in several 

 respects remarkably similar in this species and in L. liuttoni. 



EXPLANATION OF PLATE XXIII. 



Lepeophtheirus eeecsoxi. 



Female' (dorsal aspect) x . 

 Mitle „ X 25. 



Antenm« of Isfc pair, x 5G. 

 2nd „ X 56. 

 !Mouth-sucker, x 5G. 

 Foot-jaw of 1st pair, x 56. 

 2nd „ X 56. 

 8. Foot of 1st pair, x 56. 

 2nd „ X 56. 

 .3rd „ X 40. 

 Fig. 11. Abdomen and caudal setae, x 56. 



