BY R. VON LENDENFELD, PH.D. 927 



Hemisphere.) All the specimens were collected near Sydney, and 

 the species is described as blue to gray, No one mentions the 

 bright brown colour, which is so very striking. The latest of these 

 observers was T. Huxley in the year 1845. Has the change taken 

 place since that time 1 Have we to assume that a new species or 

 variety has been produced within the last forty years 1 



If this paper should be read by anyone who has access to the 

 original type specimens of Quoy et Gaimard or Huxley, it would 

 be well worth while to examine them so as to find out whether 

 they can detect any Zooxanthellse in them or not. 



Two years ago I described a most beautiful Medusa of Port 

 Phillip as Cyanea Annaskala, R. v. L. Although this species 

 appears in millions in the place mentioned there is no record of its 

 having been found anvwhere else, and also I have not found it in 

 any other locality until lately. In September a few specimens 

 appeared in Port Jackson, which although slightly different in 

 colour and size must doubtlessly be referred to my species Cyanea 

 Annaskala. Whilst the Melbourne specimens appeai-ed never to 

 grow beyond 10 Cm. in diameter, the Sydney specimens attain a 

 diameter of 20 Cm. and more. There is hardly a doubt that this 

 Medusa grows to a larger size in the warmer water of the 

 equatorial current than in the cold water that comes from the 

 South Pole, the Fauna of which is comparatively poor. There 

 exists also a difference in the colour of the mouth-arms. The 

 Melbourne specimens possess mouth arms, which are deep purple 

 throughout, whilst the purple colour in the Sydney specimens is 

 found only at the margin. 



The margin, which is much thicker than the proximal parts of 

 the mouth-arms, consists of a number of cells in the Ectoderm, 

 which here is composed of many layers. The pigment is found in 

 these cells exclusively and not also in the supporting lamella as in 

 the Melbourne specimen. 



Among the thousands of specimens which I examined at 

 Melbourne I did not find a single form which might be considered 

 as a transient variety. The moutharms of all had quite the same 

 coloui", a fact to which I drew attention at the time. As also the 



