238 Marine Microbiology 



of the stations worked, 5 per cent of these stations being within 

 120 miles of the coast. On one occasion in the Coral Sea ( Quick- 

 match Station 1), there were about 5 X lO^ nannoplankton 

 organisms {Chromulina) per liter and no larger phytoplankton. 

 Table 1 shows the composition (organisms per field) of 

 (a) Samples taken at random from oceanic stations in the Coral 

 Sea; and (b) samples also taken at random from the Southern 

 Tasman Sea. 



THE IMPORTANCE OF COLORLESS FLAGELLATES 



The ratio of chlorophyll-bearing to chlorophyll-less micro- 

 organisms has been studied by first counting the number show- 

 ing the autofluorescence of chlorophyll in blue-violet light, and 

 then counting those giving a green fluorescence induced by 

 acridine orange. The same samples were used for both counts. 

 As both types of organism stain with acridine orange, the chloro- 

 phyll count was subtracted from the acridine orange count. At 

 the on-shore Cronulla stations, the ratio ranged from 3:1 to 1:3, 

 while the oceanic stations ranged from 1:2 to 1:100. Most phy- 

 toplankton counts do not differentiate between these potential 

 autotrophs and the heterotrophs, and such differentiation be- 

 comes important if one wishes to correlate phytoplankton num- 

 bers with productivity, nutrients, etc. 



THE RELATIVE IMPORTANCE OF 

 NAKED DINOFLAGELLATES 



The dearth of naked dinoflagellates in formalized material 

 is reflected in the taxonomic paper of Wood, (2) where only 

 eleven unamiored species were described out of a total of 280, 

 though many smaller forms were missed by the nets used for those 

 studies. A study of living phytoplankton from the Coral Sea re- 

 sulted in the recording of 130 species of naked dinoflagellates, 

 and, at times, these forms made up about 50 per cent of the 

 total phytoplankton. In the Southern Tasman, the naked flagel- 

 lates were not so important, but they did not completely dis- 

 appear even at the IIC isothemi. 



MYXOPHYCEAE IN TROPICAL WATERS 



Bernard and Lecal (1) record the importance of tlie 



