130 
PACIFIC SCIENCE, Vol. VII, January, 1953 
of the Brevirostris Group and the only other 
Hawaiian species with which it could be con- 
fused, by the relative lengths of the second 
carpal articles of the second legs, almost 3.0 
times the length of the first article in C. 
platyunguiculata and only 0.7 its length in this 
species; by the excessive setae on the third 
legs in C. platyunguiculata and by the thicker 
chela in that species. Other characteristics for 
the separation of the two species are found in 
the frontal region of the carapace, the relative 
lengths of the scaphocerite and the anten- 
nular and antennal peduncles, and the small 
chelae of the males and females. 
DISTRIBUTION: This specimen was collected 
on the sand flats of Kaneohe Bay, Oahu, 
where the water is only a few inches deep at 
low tide. For the possible habitat of this 
species, see the discussion under C platyun- 
guiculata. 
It has been reported from Zanzibar, Dji- 
bouti, and the Mergui Archipelago (Andaman 
Sea) in the Indian Ocean, from the Nether- 
lands Indies, Japan, and near Queensland in 
the Pacific, but not previously from the cen- 
tral Pacific region. 
Crangon platyunguiculata sp. nov. 
Fig. 47 a-k 
TYPE SPECIMEN: A female 25 mm. long, 
collected at Waialua Bay, Oahu, from old 
coral in about 6 feet of water. Paratypes, two 
males, one 20 mm., the other 10 mm. long, 
from the same location (U. S. N. M. 93461). 
DESCRIPTION: Rostrum small, triangular, as 
long as broad at base, tip reaching less than 
0.5 length of visible portion of first anten- 
nular article. Rostral carina distinct and con- 
tinuous from tip of rostrum to between orbital 
hoods, thereafter more rounded and less well 
defined but continuing to posterior margin 
of hoods. Orbital hoods large, rounded an- 
teriorly, frontal margin reaching to middle of 
rostrum; posteriorly merging with convexity 
of carapace; in lateral view higher than rostral 
base; transparent, hence outlines of rostral 
base visible through hoods in lateral view; 
much larger than eyes. 
Antennal peduncle long, rather slender. 
Second article 3 times as long as broad, 1.3 
times as long as first article, twice as long as 
third article. Stylocerite large, with lateral 
spine poorly developed, reaching only slight- 
ly beyond curvature of scale; tip reaching 
almost to end of first antennular article. Later- 
al spine of basicerite well developed, slightly 
shorter than stylocerite. Scaphocerite large, 
with heavy outer spine; lateral margins slight- 
ly concave, tip relatively heavy and somewhat 
incurved; squamous portion narrow. Carpo- 
cerite reaching beyond end of scaphocerite, 
which slightly exceeds end of antennular 
peduncle. 
Third maxillipeds of usual form, but inner 
faces of terminal and subterminal articles very 
densely clothed with setae and short bristles. 
Large chela compressed, 2.3 times as high 
as thick, 2.3 times as long as high, margins 
rounded, broadest near middle, slightly taper- 
ing proximally, somewhat more distally. Up- 
per margin proximal to dactylus with deep 
transverse furrow expanding into shallow de- 
pressed area on each face. Margin above 
articulation of dactylus with shallow excava- 
tion adjacent to palmar adhesive plaque for 
accommodation of crest of dactylus when 
flexed. Dactylus 0.3 length of chela, crested, 
strongly arcuate, heavy, 2.4 times as long as 
wide, compressed like chela. Chela with nu- 
merous long setae on margins. Carpus of 
usual form. Merus 2.5 times as long as broad, 
superior distal margin rounded, inferior in- 
ternal margin with 2 strong movable spines, 
one about middle, other more distal, weak 
but acute subterminal tooth; long setae found 
only on distal portions of article. 
Small chela of female somewhat com- 
pressed, 3.5 times as long as broad, fingers 
between 0.5 and 0.6 of length; surfaces with- 
out grooves or depressions; articulation of 
dactylus flanked by small subacute projection; 
fingers quite rounded. Entire chela heavily 
covered with long setae, especially along up- 
