There are few more beautiful plants among the filiform Algae 

 of our coasts, and not many more rare than the subject of this 

 plate, which, though found in several distant localities is no 

 where abundant in Britain. It is, indeed, a species of the south 

 of Europe which finds its northern limit in our seas, where it 

 does not reach much more than half the size that it attains in 

 the Mediterranean. Specimens from the shores of Italy are 

 nearly as large and bushy as 8. scoparia, but much more slender in 

 all their parts. Our British individuals, except those from Jersey, 

 are so feeble, and have so different an aspect, that Dr. Greville, 

 who first figured them in his beautiful Cryptogamic Flora, regards 

 them as belonging to a different and peculiar species, which he calls 

 8. hypnoides. A careful comparison with numerous continental 

 specimens from various quarters has led me to an opposite con- 

 clusion, the differences appearing to me to be merely such as may 

 be fairly referred to climate. The Mediterranean specimens of 

 Grateloupia filicina are quite as unlike the British ones as those 

 of the Mediterranean 8phacelaria filicina are to ours. There is 

 no difference in the microscopic characters of the ramuli, or in 

 their disposition, if the specimens have respectively been collected 

 at the same season. Between the winter and summer states of 

 this species, however, the differences are so great, that Agardh 

 formerly constituted them two species, his 8. simpliciuscula, 

 which has its pinnules subsimple, being the winter state of 

 S. filicina. A similar difference between the summer and winter 

 appearance of 8. scoparia has already been pointed out. Indeed, 

 so great is the variableness of aspect which specimens at different 

 ages present, among the 8pliacelarice, that, as Meneghini well 

 remarks, the greatest caution should be exercised by authors 

 who propose new species ; and the plants should be watched in 

 their place of growth from their first appearance to maturity. 

 But this is often no easy matter, especially with such rare plants 

 as the present. Since our plate has been prepared Miss Turner 

 has communicated from Jersey a magnificent specimen," fully as 

 large as one from the south of Europe, and covered with fructi- 

 fication. I regret that it is too late to add a representation of 

 the spore to the analysis already given. 



Fig. 1. Spiiacelauia filicina : — the natural size. 2. A branch. 3. A pinna. 

 4. Cross section of the stem. 



