x Proceedings of the Royal Irish Academy. 



10— PHANEEOGAMIA AND PTERIDOPHYTA. 

 The observations of the ornithologists, carried out and published since the 

 date of this report, throw light on the question of bird migration into Clare 

 Island. They show that in hard weather large influxes of birds take place 

 (see Part 20, p. 3). The remarks on this point on pp. 85, 86 of my report 

 therefore need modification. It is clear that the influence of birds in bringing 

 seeds into Clare Island is greater than I had assumed on the evidence 

 available at the time. 



As regards the question of the dispersal of seeds by water (Part 10, 

 pp. 60-62), a body of detailed evidence regarding the power of floating in 

 water of seeds will be found in my paper " On the Buoyancy of the Seeds of 

 some Britannic Plants," Sui. Proc. E. Dublin Soc, N.S. xiv, No. 3 (1913). 

 Here are given the results of experiments on the floating power of the seeds 

 of some 800 species, undertaken as a continuation of the Clare Island study 

 of dispersal. The result confirms the estimate originally made by Darwin, 

 that about 10 per cent of a flora have seeds capable of floating. 



B. Lloyd Praeger. 

 15.— MAPJXE ALGAE. 

 Errata. 

 p. 95 Myriactis stdlata, Batt., should read Myrkictis dclhdata, Batt. 

 p. 124 Acrothrix mirabilis, Kylin, should read Acrothrix yracilis, Kylin 

 (as listed on p. 96), throughout the paragraph. 



Addenda. 



There are no additions or corrections to be made to the list of species 

 published, but two recent papers bearing on the Clare Island flora may be 

 noted. 



Lemolxe, P. " Melobesiees de l'Ouest de l'lrlande " (Nouv. Arch. Mus. 

 Hist. Nat, v, 1913, pp. 121-145). Here the authoress deals in further detail 

 with the Clare Island Melohesieae reported on by her in 1912 (see Part 15, 

 pp. 145-151), the auotomical structure of the more interesting species being 

 described at length and illustrated. 



Cottox, A. D. " The distribution of certain British Algae " ( Journ. Bot. lii. 

 1914, pp. 35-40). With the help of this note, which deals with the coast-line 

 of the West of England and Wales, a more accurate statement can be made 

 than was possible in 1912 with regard to the distribution in the British Isles 

 of the interesting algae Ptilota plumosa, Callitliamnion arbmcula, and Codium 

 mucronatum var. atlantkum. There is still no evidence that the last-named 

 occurs in England or Wales. 



A. D. Cotton, 



