446 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxxv. 



are very large and arranged in the form of parenthesis marks; the in- 

 dividual cells are also large, and there are about twelve in each gland. 

 The spermatophores are large, more or less spherical, and are fastened 

 to the ventral surface of the genital segment; their ducts lie side by 

 side in the space between the posterior lobes and apparently do not 

 cross each other at the mid line. 



Total length, 11.75 mm. Length of carapace, 6.5 mm.; of the 

 genital segment, 2.75 mm. ; of the egg strings, 10.5 mm. Width of 

 carapace, 7 mm.; of genital segment, 2.6 mm. 



Color.— A delicate yellowish pink, the chitin ribs and thickenings 

 of the carapace a dark purple, the internal oviducts a light orange, 

 the external egg cases a straw yellow. These colors are blended 

 harmoniously and make the species at once the most highly colored 

 and the most beautiful of its genus. 



Male. — Carapace similar to that of the female, but relatively much 

 larger, three-fifths of the entire length and four times as wide as the 

 genital segment. Eyes also relatively larger; posterior lobes of the 

 carapace narrower and longer. 



Free segment three-quarters as wide as the genital segment, but 

 shorter than in the female. Genital segment ovate, with the fifth 

 and sixth segments distinctly differentiated on both dorsal and 

 ventral surfaces, each of the two bearing a pair of large rudimentary 

 legs armed with spines. 



The sixth legs are at the posterior corners and project backward as 

 large lobes; the fifth pair are just in front of them and project as 

 equally large lateral lobes from the sides of the segment. Abdomen 

 two-jointed, the basal joint only one-fourth the length of the termi- 

 nal; anal lamina' larger than in the female and armed with longer 

 setae. Appendages similar to those of the female, with the usual 

 sexual differences in the second antenna 1 , first maxillae, and second 

 maxillipeds. The latter are especially large and powerful, as can 

 be seen in fig. 46. The second maxillae are very unlike those of the 

 female in that they show scarcely any bifurcation except at the very 

 tip (fig. 45). 



The mouth tube is more slender and fully as long as the second 

 maxillae. The structure of the genital segment is well shown in the 

 ventral view given in fig. 48. The coiling of the sperm duct just 

 before entering the receptacle is especially noteworthy. 



Total length, 6.6 mm. Length of carapace, 4.1 mm.; of genital 

 segment, 1.2 mm. Width of carapace, 4.2 mm.; of genital segment, 

 1.1 nun. 



Color. — The same as in the female. 



Young female.— Carapace more elliptical than in the adult, longer 

 than wide. Free segment as wide as the genital segment and more 

 than half as long, its sides not protruding much at the bases of the 



