NO. ir,80. NE W SPECIES OF CA LIGIN.E- WILSON. 615 



Male. — Carapace orbicular as in the female, but slightly longer than 

 wide and fully three-fifths the entire length. Rostrum and carapace 

 areas as in the female. Free segment short, five-ninths as wide as 

 the genital segment; the latter elliptical, a little longer than wide, 

 with evenly rounded sides; fifth legs not visible dorsally. 



Abdomen only two-thirds the length of the genital segment, the 

 same width as the free segment and two-jointed. But the joints are 

 not as distinct as in the female and the basal one is only one-fourth 

 as long as the terminal. The anal lamina? are large, widely separated, 

 and each is armed with two long plumose sette and three short spines. 



Appendages as in the female, except that all, and particularly the 

 swimming legs, are larger and better developed. But the chief dif- 

 ference lies in the second antenna\; in the female these were degen- 

 erated to mere stumps, entirely useless. But in the male we find a 

 pair of large and strong organs tipped with powerful pinchers, and 

 evidently used for clasping organs. They are not only nondegenerate, 

 but are actually better developed than in the males of other genera. 

 They are three-jointed, the basal and second joints about the same 

 size, the latter with a sharp projection on the inner margin at the 

 distal end which forms a chela with the small and strongly curved 

 end claw. 



Reproductive organs as in Caligus, the testes rather small and 

 situated far back, just in front of the groove separating the cephalic 

 and thoracic areas. The vas deferens can be easily followed back 

 to the semen receptacles which fill nearly the whole of the genital 

 segment on either side of the intestine. 



Inside the receptacles can be seen the large spermatophores, with 

 their short coiled tul)es through which the contents are emptied into 

 the semen receptacles of the female after the spermatophores have 

 been fastened to the outside of the fenuile's genital segment during 

 coition. 



Total length, 2.34 mm.; length of carapace, 1.4 mm.; length of 

 genital segment, 0.55 mm.; length of abdomen, 0.36 mm.; width of 

 carapace, 1.3 mm. 



Color as in the female, the reddish pigment rather more prominent. 



Nauplins. — Body wide, spindle shaped, the frontal margin broad 

 and l)ut slightly curved with prominent lateral angles. Posterior end 

 narrowed considerably more than the anterior, but with ])rominent 

 angles at the bases of the balancers. Eye spot large and projecting 

 from the anterior nuirgin, deep wine-red in color. (Fig. 100.) 



Pigment rust-colored with the red ]irominent, arranged in a nar- 

 row line parallel with either side of the b(Kly close to the margin, 

 and extending from the balancers almost to the eye spot. 



The outer margins of these lines are (|uite regular, but the inner 

 margins are broken and ragged. Each line is enlarged at the anterior 



