[fraser] COPEPODS PARASITIC ON FISH 57 



claw. The three distal segments are together equal in length to the 

 basal segment. 



Total length 5-6 mm., length of carapace 2-4, width 2-4, length 

 of genital segment 1-8, width 1-8, length of egg strings 5-5. 



Male: Body about half the length and two-thirds the width of 

 the female. Carapace slightly longer than broad, more nearly square 

 than circular; posterior sinuses narrow but deep; lateral lobes narrow; 

 median segment wide but narrowing anteriorly and posteriorly. 

 Genital segment broader than long, rounded more anteriorly than 

 posteriorly ; there are three setse from each of the fifth and sixth pairs 

 of legs. The abdominal segment as long as broad, nearly the same 

 width throughout. The anal laminae are well separated; each is pro- 

 vided with three strong setse, with one short one interiorly and two 

 exteriorly to these. In the appendages, the main differences, as com- 

 pared with the female, are in the second antennae, first maxillae and 

 maxillipeds. The second antenna has a stronger hook at the base of 

 the terminal joint and an extra one near the centre of the joint. The 

 first maxilla is similar in shape to that of the female but on the inner 

 side there is a tubercle at the base of the ramus, from which projects 

 a long, claw-like spine, extended almost to the end of the ramus. The 

 maxilliped is similar in shape to that of the female but is provided 

 with a spine on the terminal joint, placed centrally and pointing to- 

 wards the tip of the joint. 



Total length 2-7 mm., length of carapace 1-7, width 1-5, length 

 of genital segment 0-5, width 0-6. 



Colour: Very light yellow, almost white, throughout. 



Nauplius: Body nearly rectangular but slightly broader at the 

 middle and tapering slightly anteriorly and posteriorly; four-sevenths 

 as broad as long; anterior end slightly rounded, posterior end truncate; 

 balancers short, far apart; No pigment noticeable. Length • 37 mm., 

 width 0-21. 



{parvicruris , referring to the small size of the fourth leg.) 

 Found in large numbers on the light surface of the starry flounder, 

 Platichthys stellatus. 



Lepeophtheirus parviventris, Wilson 



Lepeophtheirus parviventris. Wilson, Proc. U.S. Nat. Mus., vol. 28, 



1905, p. 635. 

 Wilson, Proc. U.S. Nat. Mus., vol. 35, 



1909, p. 439. 

 Wilson, Contr. Can. Biol., 1912, p. 93. 



