147 



numbers as to literally clog the gills and prevent respiration, or 

 the water may have been so deficient in oxygen as to be unfit to 

 support the higher forms of life, or they may have been so overfed 

 as to produce indigestion and sickness. No doubt any one of 

 these causes acting for weeks in succession, or a combination of 

 the whole, would be sufficient to render the entire littoral fauna 

 uidiealthy ; and every death of the larger animals would tend to 

 make the conditions worse for those that remained. I examined 

 the stomachs of both oysters and mussels, and found them full of 

 Peridinia, and in many cases the water enclosed in the shell 

 contained great quantities in a living condition. 



From what I ha\e observed of the habits of the particular 

 species of the Peridinia in question they appear to be extremely 

 social, and seek each other, and swim in lines or clouds, always 

 with a tendancy towards the light ; and, as it is probable they do 

 not extend to a great depth, the bottom fauna will not be so much 

 attected as the littoral. The sudden appearance of this organism, 

 wliich has discoloured the whole of the waters of Port Jackson 

 and destroyed a very considerable portion of its fauna, is another 

 instance of our ignorance of the various conditions which aftect 

 our marine food supplies, and shows the importance and necessity 

 of the immediate establishment of a thoroughly efficient biological 

 station. If such an Institution had been in existence during the 

 presence of this extraordinary visitation, the whole of the question 

 as to its effects on our marine fauna could have been satisfactorily 

 determined experimentally. 



I have the honour to be, Sir, your obedient servant, 



Thomas Whitelegge. 



P.S. — (7th May) The Peridinium mentioned in the above 

 report is probably a new species, and will be dealt with in a 

 further report. The organism in question made its appearance 

 in vast numbers about the middle of March, and is now 

 disappearing. — T. W . 



NOTE ON THE NIDIFICATION OF PLOWS N'OV.E^ 

 HOLLANDU:, Gould. 



The N&w Holland Snake-bird or Darter. 



By a. J. NoKTH, F.L.S. 



The Trustees of the Australian Museum haNc lately received the 

 eggs of Plolus uova;-}tullandi(£, taken by Mr. J. L. x\yres at Lake 



