NO. 1 101. PARASITIC COPEPODS—CALIGID.E— WILSON. 00 1 



ent day would yield some of the same .species, as well as many new 

 ones. 



The diagnoses of these species and the outline di-awing-s presented 

 with them are taken from the orig-inal descriptions as far as possil)le, 

 and in one or two instances additions have ])een made from later 

 authors, for which acis:no\v lodgment is duly made. Dana's species, 

 O. thymni., was obtained a long distance from the American shore, but 

 as it was found upon the same bonito which serves as host of three 

 other species here described, it is likely to be found here at an}^ time; 

 and then it is really needed for purposes of comparison, and so is here 

 included. 



CALIGUS BALISTiE Steenstrup and Liitken. 



riate XV, figs. 172-177. 



Cnligus halhix Steenstrup and Lutken, 1861, p. 356, pi. i, fig. 1. — B.xssett- 

 Smith, 1899, p. 448. 



Female. — Carapace elliptical, as wide anterior!}^ as posteriorly, more 

 than half the entire length. Frontal plates not prominent nor very 

 distinct; lunules small and widely separated. Posterior sinuses shal- 

 low and nearly parallel with the longitudinal axis; median lobe about 

 half the entire width and shorter than the lateral lobes; the latter are 

 narrow and somewhat ])ointed. 



Free segment very narrow and long, like a wasp waist, and not much 

 widened at the center through the bases of the fourth legs. Genital 

 segment obovate, well rounded anteriorly, but witli a deeply concave 

 posterior margin, leaving the lobes at the external angles short and 

 acute. 



Abdomen short and wide, only half the length of the genital segment 

 and somewhat club-shaped; anal laminae minute and armed with small 

 setaj. Egg strings about the same width as the abdomen and as long- 

 as the entire body; eggs large and well rounded, about tifty in each 

 string. 



First antennie longer and more thickl}" beset with setje than usual, 

 those at the extremity of the terminal joint being very long. vSecond 

 antenniB rather weak. Second maxillipeds with a stout basal joint and 

 a slender terminal claw, the accessory spine of the latter being much 

 nearer the tip than usual. Second maxillw slender, curved and acu- 

 minate. Furca small, base wide and short, branches very slender, 

 straight, and divergent, about twice as long as the base. Fourth legs 

 three-jointed, with four spines; the latter slender and XQvy long, all 

 four about the same length; fifth legs invisible dorsally. Total length 

 4.5 mm. Length of carapace 2.6 mm. ; width of same 2.2 mm. ; length 

 of genital segment 1.4 mm.; length of abdomen 0.0 mm.; length of 

 Q^^^ strings 4.0 mm. 



