84 



Without a thorough knowledge of the conditions under which 

 the Alga occurs in the Maitland district, it is difficult to say 

 Avhat steps should be taken with a view to its destruction. Under 

 the circumstances I can only make a few suggestions which might, 

 if carried out, tend to reduce its numbers. 



In the first place it is a well known fact that the Kotit'era or 

 Wheel-animaculte feed on small unicellular Alg» such as the one 

 in question. The Unio or Freshwater Mussel might also be tried, 

 its introduction would not be injurious to the water supply. 

 But 1 consider the best plan would be to take advantage of the 

 resting stage of the plant, and engage a staff of men to skim the 

 surface of the water. With suitable wire gauze frames vast 

 quantities might be collected and destroyed. If this method 

 were adopted for several seasons in succession the organism might 

 ultimately be eradicated. The following are a few of the more 

 important works in which this Alga is dealt with : — 



Chlaniydomonas pulvisctdus, Ehrenberg; Die Infusions thiercheii, 



1838, p. GI. 

 Chlainydo'inonas pulviscidus, Pritchard ; Infusoria, 18G1, p. 521, 



pi. 18, f. 40, 51 - 54. 



Chlaint/douiouas ■pidviscidus^ Cooke ; British Freshwater Algfe, 

 1882-4, p. 56, pi. 21, f. 3. 



Chlainydonionas pulvisculus, Bennett & Murray ; Handbook of 

 Cryptogamic Botany, 1889, pp. 186, 299, 300, 409, 417, 419. 



I have the honor to be, 



Your Obedient Servant, 



Thomas Whitelegge. 



SPECIMENS OBTAINED ON A DREDGING TRIP IN 

 PORT JACKSON, SATURDAY, 30tii MAY, 1890. 



As an instance of the very extensive Marine Fauna of Port 



' lined in one 

 determined 



Jackson, the following list of tlie various species obtained in one 

 day's dredging is given. The specimens have been c 



