of half the breadth above stated, but do not otherwise differ. The young 

 frond (Fig. 2) is simply pinnatifid. The substance is soft, carnoso-cartila- 

 ginous or somewhat membranaceous, and in drying the plant adheres 

 closely to paper, and has a glossy surface. The colour, when growing, is a 

 beautifully clear rosy-carmine, which becomes rather darker and duller in 

 dying. No fructification has yet been observed. On one or two speci- 

 mens, obconical, perforated ramuli, destined probably to contain antheridia, 

 occur. 



This very handsome species is inscribed to Dr. R. K. Gre- 

 ville, of Edinburgh, to whose ' Algae Britannicse ' the Author is 

 indebted for his earliest knowledge of the Algse ; and who is 

 particularly deserving of having a Lanrencia dedicated to him, 

 as he first reformed, on correct principles, the genus so called, 

 and which had previously contained many heterogeneous species. 



Our plant, in its ramification, greatly resembles the common 

 L. pinnatijida of the Northern Hemisphere ; but it differs so 

 remarkably in colour, — a character of greater moment among 

 the Algse than among any other class of plants, — that no algolo- 

 gist, we feel convinced, would refer it to that species. It may 

 be however regarded as the Australian representative of L. pin- 

 natiflda. 



Erom L. concinna, Mont. {L. complanata, Suhr), the only 

 southern species with which it can be confounded, it differs by 

 its alternate, not opposite ramification. 



The fructification has not yet been seen. On one or two 

 specimens I have found young " saucers," like those that pro- 

 duce antheridia in L. pinnatifida, but the antheridia had not 

 been developed. 



Fig. 1. Laurencia Grevilleana, a full-grown specimen; and 2, a young 

 specimen : — both of the natural size. 3. Apex of an ordinary ramulus, 

 bearing a top-shaped ramulus, probably a receptacle for antheridia : — mo- 

 derately magnified. 



