NO. 3556 PORTUNID CRABS—STEPHENSON AND REES ik 
ules in the metagastric region; and in having longer and more slender 
chelipeds. 
These four points of difference seem to be confirmed by examina- 
tion of Rathbun’s plate 12, figure 5. 
Portunus tenuicaudatus Stephenson 
Portunus tenuicaudatus Stephenson, 196la, pp. 114-116, figs. 2C, 3H, pls. 3 
(fig. 2), 4H, 5C. 
Mareriat.—Philippines: Sta. 5160, Tinakta I., Sulu Archipelago, 
Tawitawi Group, 5°12’40’N., 119°55’10”E., 12 fm., sand, Feb. 22, 
1908, Alb., 1 male (14 mm.). 
Remarxs.—This species is very close to P. longispinosus bidens 
(Laurie) as described and figured by Sakai. Both species have 
spiniform tubercles on the dorsal surface of the carapace, and many 
of them are identically situated. (These are not mentioned by 
Laurie, 1906.) However, P. tenuwicaudatus lacks the tubercles of 
the posterior mesobranchial regions described by Sakai, and in the 
holotype (but not in the present specimen) there is a tubercle in 
each median postcardiac region. The median frontal teeth in P. 
longispinosus bidens appear much larger than those in P. tenuicau- 
datus. It also possesses a spiniform tubercle at the end of the central 
carina of the upper surface of the hand which has no described coun- 
terpart in P. longispinosus bidens. There is marked similarity but 
not absolute identity in the pigmentation of recently collected speci- 
mens. 
Portunus Species 
Matertat.— Marshalls: 4707, Rongelap Lagoon, 2 mi. W. of 
Busch I., 20 fm.; June 21, 1946, Taylor, 1 male (18 mm.). 
Remarks.—This specimen lacks the ultimate and penultimate 
segments of the abdomen and is either P. longispinosus Rathbun 
or P. longispinosus Sakai. Its chelipeds, although long and slender, 
are less so than Sakai described. 
Portunus Species 
Materrtau.—Mearshalls: EL-160, Arno Atol, received 1952, Hiatt, 
1 damaged male (10 mm.). 
Remarxks.—This specimen cannot be identified with certainty 
because the dorsal surface of the carapace, which bears tuberculate 
elevations on some of its granular patches, is damaged. 
Portunus orbitosinus Rathbun 
FIGuRE 6 
Portunus (Amphitrite) gladiator de Haan, 1837, only p. 65, pl. 18 (fig. 1) (not 
Portunus gladiator Fabricius, 1798). 
Portunus (Achelous) orbitosinus Rathbun, 1911, p. 205, pl. 15 (fig. 11). 
