15 164 Proceedings of the Royal Irish Academy. 



so may have been overlooked; but most of the southern records of this plant 

 prove to l>e errors for Punctaria tetottiseima. It is also known from the 

 Faeroes, Kiel, and W. Sweden. 



PhyUophora Brodiaei. —Sec note on p. 134. The plant is known from Nova 

 Zemblya, Spitzbergen, E. Greenland, Iceland, Norway. Sweden, Baltic, 

 Scotland, N. England and N. Ireland, and may therefore claim to he a dis- 

 tinctly boreal species. In Clew Day it is scarce, but several colonies were 

 noted at Mulranny. 



LithothamniHtn norvegtcum. — Scattered amongst L. calcareum in Clew Bay 

 and at Koundstone. Known from Scotland, Norway, Denmark, and the N. 

 Atlantic coast of N. America. It has not been observed in the Lithothamninm 

 banks of the English or French coasts. 



T/Uhothamnium compactwn. — Madame Lemoine remarks that this is a 

 distinctly boreal species. It is known from Nova Zemblya, Spitsbergen, 

 Iceland, Norway, Greenland, and the N. Pacific coast of N. America. 



Callithamnion arbuseula. — The presence of this boreal species on the 

 Irish west coast gives the appearance of a distinct overlapping in the flora. 

 In the colder waters of the North Sea it is not known south of Yorkshire ;' and 

 on the west coast of Great Britain it descends to Ayrshire and the Isle of 

 Man. On Clare Island it is abundant, and forms a conspicuous belt, just as 

 it does in Scotland, Norway, and the Faeroes. It is recorded by Adams for 

 Minister and Leinster, and probably extends right round the Irish coast. 



Ptilotaplumos'i. —Another anomaly on the west coast. Listed by Borgescn 

 as a sub-arctic species and general in Iceland, Nova Zemblya, and Spits- 

 bergen, P. jdtmosa descends as far as Yorkshire on our east coast, and North 

 Wales and the Isle of Man on the west. In Clare Island it is plentiful on 

 the stipes of Lamina ria Cloastoni, and is washed ashore in company with 

 such southern plants as Taonia and Callymenia reniformis. Adams lists it 

 from Minister and the south of Ireland ; but as the older writers often con- 

 tused the plant with Plumaria degatis, it would be advisable to confirm its 

 presence in the southern provinces. In the London herbaria, there are no 

 specimens south of Renvyle (Co. Galway). 



(c) Other interesting species. — The most noteworthy alga in the list 

 is undoubtedly Codium mucrmatam var. atlanticum. This had either to be 

 regarded as a new and endemic species, or to be linked with the Australasian 

 C. mucroncUttm. The agreement in microscopic structure with the latter was 

 found to be so close, that it was impossible to do otherwise than regard it as a 

 form of that species. Its position on the west coasts of the British Isles is, how- 

 ever, remarkably isolated, as it is not known elsewhere in Europe, nor indeed 



1 Hatters gives an Isle of Wighl record : but this is almost certainly an error lor C. granulatum, a 

 compact form of which is not uncommon in that locality. 



