becoming greenish and at lengtb white in old-age. The substance is mem- 

 branous, and somewhat rigid from the calcareous induraent. The frond 

 does not adhere to paper in drying. 



This species, first described by Ellis ancl Solander as a species 

 of Corallina, is commonly found on reefs throughout the tropical 

 ocean of both hemispheres ; and occasionally, as on the shores 

 of South Africa and Australia, occurs in the warmer districts of 

 the temperate zone. Specimens from widely separated localities 

 scarcely vary in any tangible character. Some are rather more 

 luxuriant than others ; and the colour varies with the age or ex- 

 posure of each individual specimen, but the ramification is very 

 constantly the same in all. It is by no means common in tem- 

 perate Australia, but probably abounds in the almost unexplored 

 intratropical coasts. 



Fig. 1. Galax AURA obtusata, — the natural size. 2. Cross section of the frond. 

 3. Tabulated cells of the periphery : — magnified. 



