[fraser] COPEPODS PARASITIC ON FISH 47 



seta at the base and a small blunt, claw-like projection about two- 

 thirds the distance from the base to the point. 



The first legs have a two-jointed exopod, the basal joint unarmed, 

 the terminal one with six large setae, the endopod is three-jointed; 

 each of the two basal joints have a large seta on the inner margin and 

 hairs on the outer, the terminal joint has five setae. The arrangement 

 of the spines, and setae on the other legs are as follows: — Second 

 exopod, I-O. I-l, II-l, 1 1-4; endopod, O-O, 0-2, 0-3; third exopod, 

 I-O, I-l, I-l, 1 1-4; endopod, 0-1, I-O, II 1-2; fourth exopod, I-O, 

 I-l, I-l, II-3; endopod, 0-1, 0-1, 0-3. The fifth leg is two-jointed, 

 the first joint is rectangular, the second clavate, with a spine near the 

 centre of its outer margin and three at the tip. 



Total length l-9mm., céphalothorax, length 0-64 mm., wndth 

 0-96 mm., length of the four free thoracic segments 0-9 mm., width 

 of genital segment 0-25 mm., length of anal setae 0-3 mm., length of 

 egg strings 1 • 2 mm. 



{Cuneatns, from general shape of the body). 



Only females were obtained, these from the gills of the Pacific 

 herring, Clupea pallasii, and the gills of the shiner or small viviparous 

 perch, Cymatogaster aggregatus. 



Ergasilus turgidus new species 

 PI. I, Figs. 12-14, PI. II, Figs. 15-21 



Female. — Body long and slender, over two and a half times as long 

 as wide, narrowing gradually posteriorly. Head completely fused 

 with the first thoracic segment without any indication of the junction. 

 Carapace almost two-thirds of the body length, much arched, hence the 

 body is one-third deeper than wide, it makes a slight, blunt projection 

 anteriorly and posteriorly extending to entirely cover the second 

 thoracic segment so that it cannot be seen in dorsal view; a line 

 passes transversely across the carapace just at the base of the second 

 antennae and another about twice as far back of this as this is from the 

 anterior margin; posterior margin almost straight but slightly 

 rounded laterally. The third thoracic segment nearly as wide as the 

 posterior portion of the carapace, the fourth narrower than this and 

 the fifth still narrower. Genital segment about the same width as the 

 fifth and a little longer than the fourth and fifth together. Abdomen 

 three-jointed, the first one narrower than the genital segment and the 

 other two slightly tapering from this. Anal laminae same length as 

 the last segment, well separated, each provided with three setae, the 

 innermost one being more than twice as long as either of the other two.. 



Sec. V, Sig. 4 



