626 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxvm. 



Abdomen very small, about one-tenth the entire length, rather con- 

 ical in shape, and terminating in a pair of small anal laminae armed 

 with short plumose setae. 



Terminal joints of the first antennae long and slender, club-shaped, 

 with only a few small setae. Second antennae with a stout basal joint 

 and a long and strongly curved terminal claw. Maxillae relatively 

 very large, the first pair close to the tips of the second antennae, the 

 second pair in the usual place beside the proboscis. Each of this sec- 

 ond pair is fully as large as the entire proboscis, projects far be3 T ond 

 the tip of the latter, and is bipartite for its terminal half. Each 

 branch is the shape of a sharp cone with a wide flange or wing on 

 either side at the center. 



The proboscis is short and wide and bluntly rounded at the tip, 

 mouth opening terminal. The mandibles are long and slender, the 

 last joint short, quite strongly curved and toothed along its inner 

 margin. First maxillipeds normal ; second pair slender, the terminal 

 claw but little more than half the length of the basal joint; the acces- 

 sory spine so small as to be easily overlooked. Furca long, narrow at 

 the base but flaring rapidly toward the tip, the prongs strongly flat- 

 tened, laminate, and each divided nearly to its base by a narrow sinus, 

 leaving the secondary branches with squarely truncate ends and paral- 

 lel sides. The central sinus is a broad U -shape, with a square base and 

 slightly converging sides. 



The first swimming legs are stout, the basal joint with a short spine 

 on its posterior margin, the second joint unarmed, the terminal joint 

 as in other species. Third legs with large and powerful basal apron, 

 but with very small and weak rami, scarcely projecting from the 

 fringe along the border of the apron. Fourth legs large and stout, 

 with four joints and four spines, the longest terminal one toothed on 

 its outer margin. Fifth legs situated close to the openings of the 

 oviducts and so rudimentary as to be scarcely visible. 



Total length 12 mm. Length of carapace 7 mm. ; width of same 

 6 mm.; length of genital segment 4 mm.; length of abdomen 1.2 mm.; 

 length of egg strings 15 mm. 



Color a light yellow, beautifully marked with spots of pink or red 

 distributed all over the body and the basal joints of the fourth legs in 

 an irregular pattern. 



Male. — Carapace orbicular, as wide as long, the posterior sinuses 

 broader than in the female, the median lobe relatively narrower and 

 well rounded posteriorly, the lateral lobes not curved inward at their 

 tips. Free thoracic segment wider than the genital segment and about 

 half as long. 



Genital segment small, of about the same length and width, and 

 carrying two pairs of large papillae One pair projects backward 

 from the lateral margin about one-third the distance from its posterior 



