Local Colour-varieties o/" Scyphomedusse. 411 



is described as blue to grej. 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? Have we to assume that a new 

 species or variety has been produced within the last forty 

 years ? 



If this paper should be read by any one 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 tind 

 out whether they can detect any Zooxantliellce in them or not. 



Two years ago I described a most beautiful Medusa of Port 

 Phillip as Cyanea annaskala^ R. von L. Although this species 

 appears in millions in the place mentioned, there is no record 

 of its having been found anywhere else, and I also have not 

 found it in any other locality until lately. In September a few 

 specimens appeared in Port Jackson, which, though slightly 

 different in colour and size, must doubtlessly be referred to 

 my species Cyanea annaskala. Whilst the Melbourne speci- 

 mens appeared never to grow beyond 10 centims. in diameter, 

 the Sydney specimens attain a diameter of 20 centims. and 

 more. There is liardly 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-arras. The Melbourne specimens 

 possess mouth-arms which are deep purple throughout, whilst 

 the purple colour in the Sydney specimens is found only a^' 

 margin. 



The margin, which is much thicker than the proximal parts 

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

 derm, which is here composed of many layers. The pigment 

 is found in these cells exclusively^ and not also in the sup- 

 porting 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 con- 

 sidered as a transitional variety. The mouth-arms of all had 

 quite the same colour — a fact to which I drew attention at the 

 time, as also the few Sydney specimens which I found were 

 constant in this particular. I consider myself justified in 

 setting up provisionally two varieties of this species : — 



Cyanea annaskala jyurpurea, found as yet only in Port 

 Phillip, with mouth-arms which are richly purple throughout ; 

 and Cyanea annaskala marginata, found as yet only in Port 

 Jackson, with mouth-arms which are purple at the free 

 margin, but otherwise appear colourless. 



The purple colour in the month-arms is very similar to the 



