42 PROCEEDINGS OF THE NATIONAL MUSEUM VOL. 120 
Male pleopod: Varying in curvature with size of specimen being 
slightly curved in small and conspicuously curved in larger specimens. 
Subterminal bristles on inside varying from zero to nine. Subter- 
minal bristles on center of under surface varying from sparse to dense. 
ba} 
.* 
————__., 
eel 
— 
—d. 5 5 
ltl Renny 
ane ee 
* 
Ficure 11.—Portunus rugosus (A. Milne Edwards), male pleopods and pleopod tips, re- 
spectively. Form I: a and e¢, Philippines, Sta. 5159, Alb.; b and f, W- Australian 
Mus. Reg. No. 51-60; d, Philippines, Sta. 5157, Alb., largest male. Form II: ¢ and 
g, Philippines, Sta. 5159, 4/b. (Scales=a—d, 1 mm.; e-g, approximately 0.5 mm., 2 lines 
indicate range.) 
The most conspicuous variation is the presence of a single meta- 
gastric elevated area instead of two, as shown by the following: 
Endeavour Strait, 2 specimens; Looc, 1 specimen. 
One specimen (Port Uson, Dec. 17, 1908) possesses acute frontal 
teeth and conspicuously elevated central mesobranchial areas. Be- | 
