14 PROCEEDINGS OF THE NATIONAL MUSEUM VOL. 120 
mesogastrics; and mesobranchial ridges are longer and slightly in- 
clined. 
DistTRIBUTION.— Madagascar, Red Sea, India, and Japan. 
Genus Portunus Weber, 1795 
Portunus acerbiterminalis, new species 
FIGuRE 1; PLATE 1B 
Materiau.—East Africa: U-48-74 Saudi Arabia, Tarut Bay, Ras 
Tanura, fish pier at night, May 26, 1948, Erdmann, 1 male (frag- 
mented, two walking legs, one fifth leg missing) (16 mm., holotype, 
cat. no. 112-656); U-48-89, Saudi Arabia, Tarut Bay, 1% mi. N. of 
Ras Tanura, 100 yds. offshore, June 7, 1948, Erdmann, 1 male (19 
mm.), 1 female (missing most appendages, with only one left cheliped, 
one walking leg, one left fifth leg) (ca. 19 mm.). All specimens soft, 
initially formalin preserved. 
Descriprion.—Front: 4-lobed, upraised, protruding well beyond 
inner supraorbital angles. Medians much smaller, more rounded, 
and less projecting than laterals, which are obtusely rounded. Inner 
supraorbital angle very obtuse. ‘Two fissures on upper border of 
orbit, both slightly open. Single suborbital fissure. Suborbital 
tooth reasonably prominent. 
Anterolateral teeth: Nine, first blunt, remainder sharp; fourth, 
sixth, and eighth slightly smaller than intervening odd-numbered 
teeth. Ninth distinctly elongate. 
Carapace: Reasonably broad, approximately twice as broad as long, 
with conspicuously elevated areas (some almost tubercular), separated 
by regions with dense pubescence. Posterior-posterolateral junction 
elevated, forming an obtuse or right angle. Following areas recog- 
nizable: Protogastrics diffuse and broadly separated; mesogastrics each 
divided into two portions, median with almost ridgelike termination, 
lateral with dense cluster of granules to form a tubercle; metagastric 
continuous across midline with ridged border; central longitudinal 
patch present, running from level of protogastrics but not quite 
confluent with metagastrics; between metagastrics and cardiacs a 
small, central, transverse, granular patch; paired cardiacs, conspicu- 
ously elevated, each bearing a tubercle, broadly separate in midline; 
median postcardiac an unusually conspicuous, tuberculate elevation; 
lateral postcardiacs conspicuous, but diffuse; anterolaterals, sizable 
patch opposite third anterolateral tooth, smaller one opposite fifth, 
and smaller still opposite seventh; epibranchial feebly developed 
laterally, well developed toward center; anterior and posterior meso- 
branchials present, former with short ridgelike border sometimes 
