368 Journal of the Asiatic Society of Bengal. [Aug.-Sept., 1913. 
R.I.M.S.S. ‘‘ Investigator’’ proceeded to the Nicobar Islands 
in order to carry out a resurvey of Nankouri Harbour. 
She arrived there on March 19th and remained there till 
April 10th. It is greatly to be regretted that during this 
period my assistant did not avail himself of the opportunity to 
examples of Julis lunaris (Linn.) and an immature specimen of 
Caranz armatus (Forsk.), a single specimen of a large Holo- 
thurian, and four tow-nettings of the surface plankton. 
n 
four samples, the bulk of the catch consists of vegetable debris 
with a certain admixture of diatoms mainly Rhizosolenia and 
Chaetoceras, and a few examples of Ceratium tripos. 
The chief animal constituents were :— 
Ascidian tadpoles. Balanus cyprides. 
Crab Zoeae. Pelagic Crustacean ova. 
Copepoda. Lamellibranch larvae. 
Copepod nauplii. Sagitta sp. 
Ostracoda Polychaet larvae. 
Balanus nauplii. Echinoderm larvae. 
THE SUCCESSION OF ORGANISMS IN THE PLANKTON. 
with regard to the breeding seasons of most of the marine 
fauna, | have thought that the following notes may prove of 
interest. 
and there can be no doubt that their season extends for a 
considerable further period, for although no observations could 
be made on the Burma coast, these larvae are found to 
swarm in enormous numb : . ee 
and August. mbers in the Hoogly River during July 
