[fraser] COPEPODS PARASITIC ON FISH 51 



Male: Carapace much similar in shape to that of the female. 

 Free thoracic segment but slightly narrower than the genital segment. 

 Genital segment with length and breadth nearly equal, well rounded 

 anteriorly and posteriorly, scarcely one-third of the width of the cara- 

 pace. The fifth and sixth legs show distinctly from the dorsal side. 

 The abdomen is quadrangular, wider than long. The anal laminae 

 are relatively long, each being provided with three long plumose 

 setae and two small spines, one placed interiorly and the other ex- 

 teriorly. 



In the appendages the main differences from that of the female 

 are in the second antennae and the first maxillae. The second antenna 

 has a stout base, and the terminal claw has a small accessory claw on 

 each side of it. The first maxilla is relatively smaller than that of 

 the female ; there is a spine present rising from the shoulder of the inner 

 ramus and running parallel to it. 



Total length 3-2 mm., length of carapace 2-1, length of genital 

 segment 0-65, length of abdomen 0-4. 



Colour: Uniformly yellowish. 



Nauplius: Body oval, nearly twice as long as wide; anterior end 

 truncate, posterior end rounded; balancers of medium size. Pigment 

 present in large amount; a single large shovel-shaped mass reaches 

 almost the whole length of the body, with the tip of the shovel at the 

 posterior end; there is a small oval spot, sometimes two, in the median 

 line in which the pigment is absent. The pigment is a bright purple. 

 Length 0-39 mm., width 0-21. 



(bifidus, referring to the bifid rami of the furca.) 



Found on the outer surface of the flounder, Lepidopsetta bi- 

 lineata. 



Lepeophtheirus breviventris new species 



Pl. Ill, Figs. 36-46 



Female: Body rather small ; carapace slightly broader than long, 

 rounded anteriorly and posteriorly; lateral grooves well in from the 

 margin, transverse groove well forward; posterior sinuses deep but 

 not very wide ; lateral lobes narrow, median lobe five-ninths the width 

 of the carapace, rounded posteriorly and projecting backward farther 

 than the lateral lobes. Free thoracic segment, one-third the width of 

 the carapace. Genital segment slightly broader than long, well round- 

 ed anteriorly and posteriorly with scarcely any sign of posterior lobes 

 in dorsal view; on the ventral surface the two pairs of rudimentary 

 legs are visible but only the setae of the outer pair are visible dorsally; 



