COLLECTING 13 
may often be found in dead shells, and, in the South, in holes in 
the banks. This genus is represented by a number of species, 
some of which are quite pretty. 
WHARVES AND BRIDGES 
On the piles of wharves and bridges may often be found beau- 
tiful tubularian hydroids in large tufts just below low-water 
mark, branched hydroids looking like little shrubs, polyzoans, 
sea-anemones, mollusks, and ascidians. The species peculiar to 
these localities are the boring mollusk Teredo navalis, or ship- 
worm, the boring isopod Limnoria lignorwm, and the boring 
amphipod Chelura terebrans, all of which penetrate the wood and 
are most destructive. 
The animals and plants of tropical beaches and coral reefs are 
so various and abundant, so curious and beautiful, as to make a 
description or even an enumeration of them in a brief space diffi- 
cult. The collector is bewildered and excited when he first views 
the profusion of the wonderful forms there found. 
It is not generally known that a fine species of “stony coral” 
is common from Cape Cod southward, growing in clear water as 
an incrustation on rocks, and developing little spires as it 
advances in age. This species, the Astrangia danaé, is especially 
interesting, since it will live in a dish of clear sea-water, and the 
polyps will expand, showing a very close relationship to the sea- 
anemone. With care in changing the water this coral will live 
for days, and may be examined in its expanded condition with a 
lens of moderate power. 
The most favorable time for collecting on any beach is at the 
lowest tide, many objects being then uncovered which do not 
appear higher up on the beach. At the spring-tides, which occur 
twice a month, at the period of the new and that of the full 
moon, the ebb is especially low, and affords an opportunity to 
search for forms whose habitat is below ordinary low-water 
mark. During storms deep-water forms are often torn from their 
beds and cast upon the beach. Shore-collecting at these times is 
often very interesting. 
