SUNIER: Java Sea Plankton. 155 
However; for the examination and description of the different systematic 
groups, we desire to send material of the Java Sea plankton to those spe- 
cialists who signify their willingness to undertake the study. The plankton 
samples, that will be forwarded free of charge, have all been collected 
with the two vertical closing-nets of Plate [V and Plate V. The net of Plate IV 
is 4 M. long and 1.3 M. in diameter at the entrance. The filtering surface 
consists of silk gauze no. 3 (23 threads per 10 mm.) from the Swiss Silk 
Bolting Cloth Mfg. Co. Ltd. (Schweizerische Seidengazefabrik A. G.) at Thal, 
Ct. St. Gallen, Switzerland. 
The net of Plate V is 1.5 M. long and 0.5 M. in diameter at the entrance. 
In this case the silk gauze no. 25 (77 threads per 10 mm.) from the same 
factory is used. 
Plate IV shows the net as it appears when it is being lowered and 
hauled in catching plankton organisms. Plate V shows the closed net as 
it is hauled in catching no more plankton organisms. The closing mecha- 
nism of these nets, which has been projected by the undersigned, has 
always worked perfectly. 
The plankton samples have been preserved in seawater-formol, made 
by the addition of one volume of the commercial aqueous solution of 
formaldehyde to nineteen or even a few more volumes of sea water. 
On request special plankton catches can easily be made during the 
cruises of the Investigation Steamer “Brak” and the plankton samples thus 
acquired can be preserved or even fixed with any fluid desired. 
As a rule it will be requested that the results of the examination and 
description of the different systematic groups of the Java Sea plankton shall 
be published in “Treubia”. Authors will receive, however fifty reprints of 
their publications gratuitously, Of all species, new or previously described, 
some specimens must be returned to the Batavia Laboratory for Marine 
Investigations. The cost of returning these will also be paid by the Batavia 
Laboratory. The bulk of the material can be kept by the specialist who has 
examined and described it. As to unica it will generally be possible to 
cede them also to the specialist. 
Specialists desiring to examine and describe one or more systematic 
groups of the Java Sea plankton are kindly requested to write to the un- 
dersigned using the following address: Aan het Hoofd van het Laborato- 
rium voor het Onderzoek der Zee, Pasar Ikan, Batavia, Java, Dutch East 
Indies. 
Dr. A. L. J. SUNIER. 
Head of the Dutch East Indian Government Laboratory 
for Marine Investigation. 
