92 Hardy, Algcd of the Zoological Gardens, Melbourne, [^f^'j^^ 



thallus of the Palmella was observed to be of irregular form, 

 but rudely approximating to lenticular, ij inches diameter 

 and from i to } inch thick at middle ; of pale opaque green 

 colour, and too weakly cohering to allow of its removal from 

 the water intact. The largest, when collapsed in a phial, 

 occupied a cubic centimeter. It is probably a form of P. 

 hyalina, and is referred to that species, though the cells are 

 larger. There were also filaments of Oscillatoria scattered 

 throughout both Flamingo and Crane Pools. 



A very small pool in the sea-gull enclosure, examined at this 

 time, yielded almost negative results in algae ; there were, 

 instead, plenty of Entomostraca, Culex larvae, water-beetles. 

 Amoeba, &c., and diatoms. Macrophytes crowded this pool, 

 prominent amongst them being Typha angiistifolia and 

 Nymphea and Cyperus lucidus. 



The fish ponds, previously examined, are of small surface, 

 and of greater depth than the pools, and partly covered by 

 screens. There is a little benthos at the edges, and from this, 

 as would be expected, the algse were of character unlike those 

 of the open, shallow, bare-banked pools. Great quantities of 

 Fragillaria were a marked feature, and conspicuous desmids 

 were PleiirotcBnium Ehrenbergii and Cosmarium Hardyi. 



It is interesting to note that, excepting small quantities of 

 MerismopcBdia and Oscillatoria, the micro -flora of the Flamingo 

 Pool consists of chlorophytes, and that for long periods the 

 pool is dominated by members of the Protococcoideae, prin- 

 cipally of the family Selenastreae ; and, further, that, while the 

 water supply is largely from the Yan Yean reservoir, whence 

 several species are probably derived, the interesting Ankislro- 

 desmus is not thus accounted for, nor does the admixture of 

 Maroondah water explain its presence. It may, with others, 

 have reached the pool by atmospheric or ornithological agencies 

 from unexamined northern areas. The introductior of birds 

 from the Northern Hemisphere is a likely cause, as Mr. Le 

 Souef informs me that, although the exact locality whence 

 came the wading birds such as cranes, flamingoes, &c., is not 

 certain, their introduction to the Melbourne Zoological Gardens 

 was direct from the Calcutta market. Algal spores might 

 easily be carried in dried mud on the legs of such waders and 

 survive the drought, of less than three weeks, occasioned by 

 the voyage to Australia. Wild duck sometimes visit these 

 pools, but do not fly from the northern areas (New South 

 Wales, Queensland, and Northern Territory), wherein lie 

 unexamined waters of a possible connection chain. The intro- 

 duction of fish ova from New Zealand in wet moss (Sphagnum) 

 to the Garden hatcheries has not been overlooked as a factor 

 in distribution ; but quantities of the moss used as packing 



