3.
In a special study during the September 1959 expedition,
the abundance of black sea cucumbers on several of the more
important islets was evaluated in notes supplemented with
photographs taken of representative portions of the beach at
low tide while walking around the shore of the islet.
Sea
cucumbers are of particular importance in turning over bottom
sediments.
The results of this study have yet to be compiled, but
may be expected to contribute to the ecological picture and to
the knowledge of the biology of these sea cucumbers.
One specimen of Holothuria atra was observed in the process of transverse
fission.
A specimen of Stichopus chloronotus harboring inter-
nally a commensal fierasferoid fish was reported in “Copeia",
Sept. 19602255.
4.
are
(The principal isotopes found in the marine invertebrates
zne5 ,
9002239
C060,
Co?7,
Mn°4,
cel44y,