286 FLOEA UF PLYMOUTH SOUND 



Flora of Plymouth Sound and Adjacent Waters. 

 Preliminary Paper. 



By 



T. Joliusou, B.ISc, 



Professor of Botany iu the Royal College of Science, Dublin. 



A Government grant by the Eoyal Society enabled me to spend 

 the montlis of August and September of 1889j in the investigation 

 of unknown or obscure points in the marine algae, in the Laboratory 

 of the Marine Biological Association, Plymouth. One of my chief 

 objects was to obtain such material of the various members of the 

 GigartinaceiB, of Spyridia, Stenogramme, and other genera, as would 

 permit me to make a detailed examination of the development of the 

 fruit (cystocarp) from the earliest stage to maturity. Several of the 

 genera required were very rare or of unknown locality, and in many 

 cases only to be found by dredging. In searching for these, new 

 weeds, or new localities for known weeds, were met with, and it 

 seemed to me the notes I made would be of use to algologists. 

 Cocks, Hore, Boswarva, Gatcombe, &c., and of late years Holmes,* 

 have combined in their work to give a very full account of the 

 marine algee to be met with without the use of the dredge. For 

 twenty years Cocks, I am told, did not miss a single low tide at 

 Plymouth (or, if not, Falmouth). Up to the present our knowledge 

 of the weeds of Plymouth has been derived almost entirely from 

 shore-hunting, some of the rarest weeds being described as washed 

 ashore, so that it was a question as to whether such weeds were 

 locally established or merely "drift" specimens. In 1867 Boswarva 

 published his Flora of Plymouth Sound in the Transactions of the 

 Plymouth Atheneeum, his catalogue being compiled from the dis- 

 coveries of himself. Cocks, &c. This list appears word for word in 

 the Marine Biological Association Journal, No. 2, 1888. I am 

 permitted by Mr. Holmes to say that through a misunderstanding 

 he is stated to give the names of eight additional species. It is 

 only fair to the early algologists to point out that jive at least of 



* Through the courtesy of Mr. Holmes I have seen a list of species added by him to the 

 Flora of Devonshire (Journal of Botany). I believe I am not overstating the case in saying 

 that he has added one hundred species of algaj to the British Flora, some new to science. 



