12 PROCEEDINGS OF THE NATIONAL MUSEUM VOL. 125 
lateral posterior region lobate, lobes bearing genital openings and 
sixth legs. Sixth leg consisting of single finely plumose setule. Four 
segments present posterior to genital segment, first approximately 
equal to length of genital segment, second approximately nine-tenths 
its length, third and fourth approximately three-fourths its length. 
Posterior segments narrower than anterior, lateral margins of first 3 
almost parallel, fourth tapered posteriorly, posterior margin with 
small anal indentation and distinct lateral concavities, at place of 
attachment and articulation of caudal rami. Caudal rami (fig. 5c) 
elongate, subrectangular, with setule-bearing indentation in distal 
half of outer surface; distal surface with 3 naked setae and 1 naked 
setule, additional naked setule present on dorsal surface just proximal 
to distal end. 
Antennule (fig. 5d) 6-segmented, attached to anterior-lateral ven- 
tral surface of cephalothorax, adjacent to small, spikeshaped projec- 
tion from lateral anterior surface of cephalothorax. First segment 
(may represent 2 fused segments) strongly flattened proximally, 
rodlike distally; bearing 19 naked or very lightly plumose setules. 
Second segment approximately one-third the length of first, with 4 
naked or lightly plumose setules. Third segment approximately half 
the length of first, with 3 naked setules. Fourth segment slightly 
more than one-third the length of first, bearing 3 naked setules. Fifth 
segment slightly less than one-third the length of first, with 2 naked 
setules. Sixth segment slightly more than one-third the length of first, 
rounded distally, bearing single naked setule from medial posterior 
surface, 5 naked setules from distal surface. Antenna (fig. 5f) 4- 
segmented, situated posterior and medial to antennule base. First 
segment strongly developed, distal surface with naked setule. Second 
segment approximately half the length of first, subrectangular. Third 
segment, excluding terminal processes, slightly shorter than second 
with deep indentation in medial outer surface; distal surface with 2 
spatulate and one clawlike projection, inner lateral surface of segment 
and spatulate process with denticulated membrane or individual 
denticulations. Fourth segment arising from indentation in third, 
rodlike, bearing 7 naked setae and setules distally. 
Mandible (fig. 6a) 1-segmented, broad proximally, irregularly 
tapered distally, with spineshaped projection distally; second spine- 
shaped projection arising from distal half of posterior surface; both 
projections with denticulations, distalmost with single longitudinal 
row on posterior surface, proximal projection with 2 rows. Maxillule 
(fig. 6a) nodular, situated immediately posterior to mandible base, 
bearing 4 naked setae. Maxilla (fig. 6@) appearing 2-segmented, first 
segment swollen, nodular, second segment arising from inner lateral 
surface of first, rodlike, bearing 2 naked setules and single spatulate 
