44

Scientific Memoirs by

      The following are some of the papers relating to the commensalism of Polyps and
Crustaceans:—

      Quatrefages, Ann. Sci. Nat. Zool. (2) XX, 1843, p. 230: Wortley Ann. Mag. Nat.
Hist. (3) XII, 1863, p. 388: Semper, Zeits. wiss. Zool. XIII, 1863, p. 560: Chevreux.
Compt. Rend. Assoc. France pour l'Avance des Sciences, XIII, p. 316: Des Moulins, Act.
Soc. Linn. Bordeaux, XXVIII, 1871, p. 325: Hesse, Ann. Sci. Nat. Zool. (6) 1876:
Faurot, Compt. Rend. CI, 1885, p. 173: Aurivillius, Svensk. Vet. Akad. Handl. XXIV,
1890-91, No. 9: Milne Edwards and Bouvier, Bull. Soc. Philomath. Paris ,(8) III, 1890-91,
pp. 102,151: Bouvier, Bull. Soc. Philom. Paris. (8) 1V, 1891-92, p. 5: Fowler, Journ.
Marine Biol. Ass. II, 1891-92, p. 75: Henderson, Journ. Asiatic. Soc. Beng. 1896, pt.
2, p. 516: Hickson, Studies in Biol. Owens Coll. Manch. IV, 1899, p. 147: Alcock,
Journ. Asiatic Soc. Beng. 1899, p. 111.

      In many of the above papers further references, not here quoted, will be found.

3. Commensalism among Echinoderms.

      Among Echinoderms we have not on the " Investigator " encountered any
cases of association with other animals in which a reciprocity of benefits is
apparent.

      On a common species of Comatula , in which the arms and pinnules are
banded alternately yellow and purple, we have found a Polychaete worm and a
Galatheid crustacean, both coloured like their host, and, as it would seem, en-
tirely to their own advantage.

      A star-fish, Dictyaster xenophilus , several times dredged in the Andaman
Sea, at 170 to 290 fathoms, almost always has a (non-parasitic) Polychaete
worm firmly adherent to its broad actinal inter-radial areas, where also the eggs
of the worm are often found.

      The well known association between the Holothurian Stichopus and the
Ophidioid fish Fierasfer homei , has twice been verified: once at Kiltan Island,
in the Laccadive group, where I saw the fish dart out of, and again into, the
cloaca of a Stichopus , which I then captured; and once in the Andamans, where
I found the fish inside the body-cavity of a Stichopus that I was dissecting.

      The similar association between Holothurians and Crustacea has also been
verified. Esconced in the cloaca of a species of Mulleria I once found a species
of Finnoteres.

      The following are some of the papers in which Echinoderm commensals are referred
to:—

      J. Muller, in Ann. Mag. Nat. Hist. (2) IX, 1852, pp. 22,103; and (3) X, 1862, p. 216
(Mollusks developing in the genital glands of a Holothurian).

      J. Müller, Archiv f. Anat. u. Physiol. 1858, p. 323 (commensals and parasites of
Holothurians).