its nearest ally, by every author who has written on the subject 

 of Phycology. Dr. Greville, who at one time united it with L. 

 saccharina, has, in his last work, restored it to a place in the 

 system, remarking : — " I cannot but express some doubt re- 

 garding the claim of this beautiful Alga to be considered as 

 distinct from the preceding species (Z. saccharina). The more I 

 have studied it in a growing state, the less am I tempted to 

 speak positively on the subject. Upon the whole, however, I am 

 rather inclined to think it a true species. Having traced it from 

 its earliest appearance to its full size, I can testify that its 

 characters are preserved in every stage." I believe that most 

 observers have, at one time or other, shared in the doubts thus ex- 

 pressed by Dr. Greville, and many may be disposed to go further 

 and reject L. phyllitis from the list altogether. Among these 

 I must mention Mrs. Griffiths, who has repeatedly stated to me 

 her opinion that no good marks exist between L. phyllitis and 

 saccharina, but that the former is merely the young of the latter. 

 Tn adopting a contrary view, I have not acted hastily or without 

 comparing specimens of the young of both plants. Very recently 

 my friend Mr. Cole has laid before me a series of specimens of 

 both, tracing the growth of L. saccharina upwards, from the 

 height of half an inch to a full development, and a similar set of 

 young plants of L. phyllitis. And I must admit that, though 

 there is a close resemblance, there is a clear distinction at all 

 ages between living plants : L. saccharina being thicker, of 

 darker colour, and with a more abrupt base than L. phyllitis, 

 whose delicately membranous nature, and strictly lanceolate form, 

 are preserved to a very large size, The latter also very rapidly 

 changes colour in fresh water, while the former may be preserved 

 for some hours in that medium. 



Having said so much, I submit the matter to the investigation 

 of my fellow-students, and shall be glad to be favoured with an 

 expression of their opinions. 



Fig. 1. Laminabia phyllitis; small specimens : — of the natural size. 2. Portion 

 of the surface. 3. Section of the frond : — both highly magnified. 



