44 IOWA STUDIES IN NATURAL HISTORY 
blighted by the larve of a small blue moth. This insect seems to 
be confined to Vitilevu and some of the smaller islets around 
it, but has not yet made its appearance on the other large islands 
of the Fiji group. We were told that the Colonial Government, 
in order to ascertain their natural parasitic enemies, had a stand- 
ing offer of one hundred pounds to anyone finding them living 
elsewhere. 
Just off the southwest shore of our island was a magnificent 
patch of thriving corals of the finely branching kinds, which made 
a beautiful sight when the water was calm. Each of the hundreds 
of fine branchlets was tipped by a group of ealyces consisting of 
a madrepore and a few adjacent polyps, which were colored a 
bright bluish pink, sometimes lavender, in strong contrast to the 
soft gray brown of the rest of the branches. Wylie succeeded in 
getting some very satisfactory photographs of them when com- 
pletely submerged. We found a big head of Orbicella, perhaps 
two and one-half feet across with a dense mass of expanded polyps 
rising nearly three inches above the surface,—the finest display of 
living coral polyps I had ever seen. Here also was the largest 
anemone any of us had encountered. It must have been eighteen 
inches across the disc, but it was impossible to secure it as it 
shrank into a tiny erevice of flinty-hard rock at a touch. 
One of the most devilish contrivances I know in the way of a 
mantrap is the Tridacna or ‘‘giant elam’’ which is rather common 
on the Makuluva flats. These sometimes attain enormous propor- 
tions which make them the largest and heaviest of all modern bi- 
valves. I understand that one is used as a baptismal font at 
Notre Dame in Paris. Those at Makuluva were comparatively 
small, but extraordinarily hard and solid. They lie on the sur- 
face of the rock dorsal side down, and are firmly anchored by a 
byssus which is almost as tough as a good three-quarter inch hemp 
rope. It is impossible to tear one off with the hands, even if it 
is no more than eight inches long; indeed, a crow-bar must be 
used. The exceedingly hard valves have regularly scalloped mar- 
gins which fit each other with great nicety. When alive, the clam 
habitually holds these valves open from two to eight or ten inches, 
according to the size of the individual mollusk. If the collector, 
by an ineautious step, puts his foot between these valves, or in 
feeling with his hands under a rock gets his fingers in the trap, 
the valves snap shut with the unrelenting grip of steel, and the 
unfortunate victim is absolutely helpless, if alone on the reef. No 
