NO. 1504. AMERICAN PARASITIC COPEPODS— WILSON. 679 



bifurcation. Maxillipeds as hi the other species. Furca narrow, the 

 length four times the width, the branches short, simple, divergent, 

 pointed, leaving a V-shaped sinus onl}^ one-fov^rth or one-fifth the 

 entire length. Swimming legs all biramose, and the rami three-jointed 

 except those of the first pair and the endopods of the fourth pair, 

 which are tw^o-jointed. Fifth legs small and close to the lateral mar 

 gins on the ventral surface of the genital segment a little in front of the 

 posterior corners. Cement glands wide and reaching forward almost 

 to the anterior end of the segment; their component cells narrow. 



Total length, 5.75 mm. Length of carapace (including third thorax 

 segment), 2.5 mm. Length of genital segment, 1.57 mm.; of the 

 abdomen, 1.1 mm.; of eg^ strings, 3.1 mm. Width of carapace, 

 2.1 mm. 



Male. — Carapace like that of the female but relatively larger, being- 

 more than half the entire length. Frontal plates wide and strongly 

 arched anteriorl}^; eyes small but distinct. Second and third thorax 

 segments relativel}' wider than in the female; fourth segment the same 

 width as the genital segment, and only a trifle longer than the second and 

 third segements. Genital segment elliptical-oblong, one-fourth longer 

 than wide and not quite one-fifth the entire length. Both the fifth and 

 sixth legs are visible dorsally, the former on the lateral margins at about 

 the center of the segment, the latter at the posterior corners. Abdo- 

 men two-jointed, joints equal, but the two together at least one-half 

 shorter than the genital segment as in the female. Anal lamina nar- 

 row but nearly as long as the entire abdomen, each tipped with four 

 plumose setfe, which in turn are as long as both the abdomen and the 

 laminae. Appendages as in the female, except that the second antennie 

 are sometimes branched as in the males of the Caligina?. 



Total length, 2.75 mm. Length of carapace (including third thorax 

 segment), lA mm.; of genital segment, 0.5 mm. ; of abdomen, 0.6 mm. 

 Color of both sexes (preserved specimens) a uniform j'ellowish white 

 without pigment. 



{exilLs, slender, graceful.) 



Through the courtesy of Prof. W. A. Herdman, of the University 

 of Liverpool, the United States National Museum collection contains a 

 single cotype specimen of each sex of this species (Cat. No. 32723, 

 U.S.N.M.) which were taken from Rlimoptera javanica at Ceylon. 



TREBIUS TENUIFURCATUS Rathbun. 



Plate XV, figs. 8-10. 



Treb'ms ienuifurcatus Hathbux, 1887, p. 559, pi. xxix, figs. l-'i. — BASsEXT-SMixir, 

 1899, p. 462. 



Female. — Carapace horseshoe-shaped, wider than long, and, includ- 

 ing the third thorax segment, about one-third of the entire length. 



