144 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 115 



extending laterally as bar-shaped thickening from junction of major 

 cross and longitudinal grooves and uniting with short longitudinal 

 thickening along lateral margin. Additional grooves present though 

 indistinct. Eyes distinct, in anterior fourth of cephalothorax; inner 

 margins contiguous on median longitudinal axis of body (fig. 2a). 



Fourth thoracic leg-bearing segment short, wider than long, pro- 

 jecting slightly into median cephalothoracic area; covered dorsally 

 by single, platelike structure protruding laterally at region of fourth 

 thoracic leg attachment, in middle of segment. Posterior margin of 

 segment, at junction with genital segment, distinct. 



Genital segment ovoid, wider than long, lateral surfaces projecting 

 slightly past flat posterior margin of middle of segment; posterior 

 margins of lateral extensions almost flat, bearing two minute tubercles, 

 the fifth legs; outer tubercle with minute, plumose seta, inner with two 

 (fig. 26). 



Abdomen indistinctly two-segmented, attached to posterior surface 

 of genital segment. Division between first and second segments dis- 

 continuous, first segment differentiated by rounded lateral margins. 

 Second segment four times length of first, posterior lateral corners 

 slightly flared (fig. 2b). 



Antennule two-segmented, excluding frontal plates, attached to 

 frontal region under lateral, free surface of lunule. First segment 

 irregularly diamond-shaped, greatest width about two-thirds greatest 

 length. Distal half of anterior surface and distal surface of first seg- 

 ment with about 22 plumose setae. Second segment elongate, slightly 

 longer than half length of fii'st segment. Second segment with naked 

 seta from distal portion of posterior margin and 13 naked setae from 

 distal surface (fig. 2d). 



Second antenna three-segmented, attached along entire surface of 

 first segment to ventral surface of cephalothorax just posterior to 

 lunule and slightly medial to base of antennule. First segment long, 

 equal to length of second segment; distal surface forming articular 

 surface for second segment. Second segment well developed, broader 

 proximally than distally; middle of anterior surface with poorly devel- 

 oped adhesion surface; second adhesion surface present as a few ser- 

 rated ridges on inner anterior surface in same area. Third adhesion 

 surface present on distal end of small, lobate protrusion of distal por- 

 tion of anterior surface of second segment. Distal surface of second 

 segment irregular, inner portion sloping proximally, outer portion with 

 flat margin; both inner and outer surfaces concave, inner portion re- 

 ceiving ball-shaped proximal end of third segment. Third segment 

 short, proximal end heavily chitinized; with slightly curved, short, 

 strongly developed terminal process projecting at sharp angle to seg- 

 ment. Two setalike accessory processes present on third segment, 



