NO. 1404. PARASITIC CO PEPODS—CALIGIDM— WILSON. 563 



Furca much narrower than in tlic female, branches close together 

 and nearl\" parallel, de8tro3^ing- the hourglass outline. 



Third legs larger than in the female, attached nearer the posterior 

 border of the carapace, and projecting laterall}' to the edge of the 

 carapace, and posteriorly to the center of the genital segment. The 

 basal joint of each is fully as large as the genital segment, and being 

 transparent the longitudinal fibers of the nuLscles show through plainly 

 and give tlu' central portion a sti-iated appearance. The fourth legs 

 are relatively nuich longer than those of the female. 



Total length, female ;^).Co \nn\.\ male 3 mm. Length of carapace, 

 female 2 mm.; male l.H mm. Length of genital segment, female 0.84: 

 mm.; male i».5 nun. Length of abdomen, female 0.r»5 nnu.; male 0.6 

 mm. Length of (^^g, strings !.!> miu. 



Chilli mm. — Carapace considerably more than half the entire length, 

 ov^ate, strongly narrowed anteriorly. Frontal plates large and well 

 defined. Posterior simises narrow and neai'ly parallel, the median lobe 

 proportionally a little wider and more squarel}' truncated posteriorly 

 than in the adult (fig. .53). 



First antennii? large, prominent, and well armed with plumose setse 

 and s])ines. Free segment very short, but as wide as the genital seg- 

 ment. The latter is barrel-shaped. one-(iuarter \vider than long with 

 evenly rounded sides and s(|uarely truncatiHl anterior and posterior 

 l)orders. 



The two abdomen segments are about the same relative size as in the 

 adult, but compai'ed with the genital segiuent they are nuich wider, in 

 fact almost as wide as the genital segment itself. 



The anal lamiiue are small(M" than in the adult and their plumose 

 setaj ar(^ shorter. The appendages a})pear about the same with the 

 exception that the second, as well as the third swimming legs show 

 posterior to the carapace in dorsal view. Total length 1.75 mm. 

 Length of carapace 1 nun.; width of the same O.S mm. Length of 

 genital segment 0.3 nun. Length of al)domen 0.4 nun. 



Color, pale straw yellow, covered on both the dorsal and ventral sur- 

 faces with scattered spots of :i rusty brown pigment. In some speci- 

 mens these spots are few in munl)er and not noticeable, but in the great 

 majority of instances they are cpiite numerous ajid at once catch the 

 e\'e, particularly on the dorsal surface of the genital segment. 



{/'({ftfs, rust color; iiKfculdtn.s^ spotted.) 



Specimens belonging to this species were olitained by the author 

 from F'linilulus iiidjalis and F. Iniei'oditux. ■ 



The}' are more often found upon the former ])ut are not at all com- 

 mon, a careful examination of fi^e hundred of these minnows yielding 

 barely half a dozen specimens. The National Museum collection also 

 includes three specimens taken ])v Vinal N. Fdwards, one from a mul- 

 let {Mugil cej) ha />/.'<), and the other two from the surface at the Fish 



