84 
180 ° 170 ® 160 ° 150 ° 
Hawaiian I $. 
Fig. 1. Islands from which collections are reported 
upon in this study. 
spaces; 6 ft deep. All shrimp collected were 
from the dead bases, none from the living 
A crop ora. 
BC 8. A dead, coherent head of coral; 6 ft 
deep. 
BC 9. A dead head of encrusting coral with 
numerous large cavities and passages; 14 ft deep. 
BC 10. From several solid coral fragments; 
2-6 ft deep. 
Stations 11-18 were along the ocean reef on 
the leeward (southwest) side of the atoll. Here 
the reef varied from about 140 to over 200 
yards wide. The uppermost edge was a boulder 
rampart, with a sand beach below; below the 
sand zone there was a zone of consolidated beach 
rock, some wave-polished and some erosion- 
pitted. The reef flat proper was flat and without 
salient features except for occasional scattered 
boulders; its surface was covered with a dense 
algal mat about 1 inch thick. The seaward side 
of the reef was broken into surge channels with- 
out any coralline algal ridge. 
BC 11, 12, 13. Coral blocks covered with 
algal mat found at end of surge channels. 
BC 14. Heads of growing Porites sp. shaped 
like inverted wash pans; fourth head of similar 
shape, 13 inches in diameter and 4 inches thick, 
but dead and covered with a thick mat of algae; 
all from the middle reef flat at about 0 ft tidal 
PACIFIC SCIENCE, Vol. XVIII, January 1964 I 
level. On living heads and bases only about six 
alpheids were collected; but on the dead head j 
specimens were numerous, most being found be- 
tween the head and the algal mat, but with some 
occupying superficial holes and fissures in the 
head proper. 
BC 15. Loosely consolidated masses of coral- 
line algae, with many openings and passages; 
from head of surge channel, outermost reef. 
BC 16. Consolidated coralline rock (appar- 
ently largely coralline algae) ; about 10 ft shore- 
ward from head of surge channel. 
BC 17. Pocillopora meandrina Verrill; from 
head of surge channel. All specimens except A. 
lottini Guerin and Synalphem char on (Heller) 
from dead coral at base of head. 
BC 18. Dead and overgrown head of Pocil- 
lopora; from middle reef flat, 40 ft from beach 
limestone margin. 
Stations 19 and 20 were located on the flour- 
ishing coral growths immediately within the 
lagoon from the sole pass from the ocean. Here 
at both incoming and outflowing tides the cur- 
rent was so strong that slower boats could not 
breast it; collecting was possible only during 
periods of slack water. While all pieces of coral, 
living and dead, examined had a minimal ah 
pheid population (only 24 specimens were col- 
lected in about 5 hr of work ) , the snapping of 
the shrimp was audible and indicated a much 
171° 4 o' 
Fig. 2. Canton Atoll, Phoenix Islands, showing col- 
lecting stations. The dotted line indicates the 10- 
fathom depth. (Taken from U. S. Hydrographic Of- 
fice Chart #5740.) 
