638 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
Excretion in Holothurians.* — M. E. Herouard treats with some 
severity the recent work of E. Schultz on this subject. It is comforting 
however, to note that however erroneous Mr. Schultz’s work may be it 
confirms the conclusions to which M. Herouard has been drawn. 
New Comatula.f — Mr. Jiuta Hara has found on the coast line near 
Misaki, Japan, a species of Antedon which he believes to be new and 
which he calls A. macrodiscus , belonging to the A. milberti group of the 
late P. H. Carpenter. It appears to exhibit differences from any 
described species which justify him in regarding it as new. 
Ccelentera. 
Commensalism in Madreporaria4 — M. E. L. Bouvier commences 
his memoir with a note from M- Jousseaume, who collected at Aden 
the materials on which the work is based. This gentleman begins 
with referring to the error of Deshayes, who described the tube made 
by a worm in a coral as a new genus of mollusc. He says that he has 
himself found in blocks of Madreporaria worm-tubes of so great a size 
that he would certainly have taken them for the shell of a mollusc if he 
had not seen the animal. As, however, one has not always the animal 
to guide one, it is as well to know what are the differences between shell- 
tubes and worm tubes. The former are so loosely attached to their madre- 
poric envelope that with a little patience they can always be separated from 
it. Those of Annelids, on the other hand, are so intimately connected 
by their outer layers with the madreporic mass that it is impossible to 
isolate them, or to obtain the smallest piece without breaking them. 
M. Jousseaume gives an interesting account of his experiences when 
collecting, and as he has been able to see the creatures alive, his opinion 
as to the extent of the connection between the worm and the coral is of 
importance. He believes that the death of one destroys for the other 
certain elements of vitality connected with their common life, and in 
this particular case he thinks that the cause is to be sought for in 
respiration. 
M. Bouvier points out that Milne-Edwards and Haime, and not 
Deshayes, were the first to suppose that there was a commensalism 
between certain Madreporaria and Gastropod Molluscs. As is now 
well known, worms seize upon corals belonging to three different 
families, and four different species. In addition to these four now well- 
known forms, M. Bouvier is enabled to add a fifth — a fossil Eetero- 
psammia. He comes to the conclusion that the coral and its commensal 
worm choose, the one for support, the other for shelter, an empty 
Gastropod shell. What the species of Gastropod is does not matter so 
long as the shell be small. The spiral tube which succeeds the shell 
does not belong in any way to it, but is secreted by the worm in propor- 
tion as the coral increases in size. 
Two new species of commensal forms are described. One is called 
Aspidosiphon heteropsammarium , and the other A. michelini. The same 
species of coral may live commensally with either of these two species 
* Bull. Soc. Zool. France, xx. (1895) pp. 161-5 (2 figs.), 
f Zool. Mag., vii. (1895) pp. 115 and 116. 
x Ann. Sci. Nat., xx. (1895) pp. 1-32 (1 pi.). 
