Volume 71, Issue 6
June 1970, pages 221-260
pp 221-225 June 1970
Two new varieties underScleria lithosperma (L.) Sw. are described from South India with illustrations together with a key.
pp 226-229 June 1970
The paper deals with three species of flowering plants of whichIndigofera duthiei Drum. ex Naik is new to Science.Amaranthus dubius Mart. ex Thell. is a new record for India.Biophytum helenae Busc.et Musch. is the correct name of the plant widely occurring in India and recorded asB. sensitivum DC.
pp 230-246 June 1970
The depths of occurrence of oxygen maxima and minima have been studied in the upper 500 meters of the north-western Indian Ocean (including Arabian Sea and Laccadive Sea). The data collected by various ships during the International Indian Ocean Expedition were pooled into one degree grids and analysed for getting patterns of distribution—seasonally and regionally.
The studies reveal that there is much variation in the depths of occurrence of oxygen maxima and minima in different areas and different seasons in the north-western Indian Ocean. Along the continental shelf all over the Arabian Sea, biological activity appears to play a predominant role in controlling the oxygen content, while in the open parts of the ocean the depths of occurrence of oxygen maxima and minima mainly appear to be governed by the water movements, circulation and mixing. one of the important observations is the existence of stagnant or near-stagnant conditions in the more central part of the Arabian Sea, restricting the exchange of water masses with the adjoining seas.
pp 247-260 June 1970
The seasonal cycles of organic matter and chlorophyll at some beaches of the Kerala Coast were studied in relation to the abundance of the interstitial fauna at one of the beaches. The faunal abundance showed no definite correlation either with organic matter or with chlorophyll. There was no correlation between organic matter and chlorophyll, which indicates that the occurrence of one is independent of the other. The maximum density of interstitial fauna at the Cochin beach was found to be at the mid-tide level. The most abundant groups on the beach were the ciliates, foraminiferans, nematodes and harpacticoids. Less abundant forms included the gastrotrichs, turbellarians, polychaetes, archiannelids, oligochaetes and isopods.