of Good Hope individuals. In general aspect and size, and in 

 the groat abundance of sori, the two very nearly agree, but the 

 Cape plant is of firmer substance and less translucent than the 

 Tasnianian, and its sori are scarcely so much drawn out or 

 lengthened. These differences however appear to me to be un- 

 important if we bear in mind that the Cape specimens were 

 grown in the open sea, exposed to the rough billows of the 

 *' Cape of Storms," while the Tasmanian flourished in the deep 

 and quiet estuary of the Tamar, a locality which is well known 

 to favour great luxuriance and delicacy of frond, and an attenua- 

 tion of parts, in all other Algae : while it is also known that an 

 exposed, stormy coast has a contrary influence. 



Fig. 1. DiCTYOTA NjEvosa, — tlie natural size. 2. Small portion of the frond. 

 3. Spores : — magnified. 



