16 166 Proceedings of the Royal Irish Academy. 



mere list ol >pecies found floating, either of their own accord, or entangled 

 with debris, would be of interest, and oould he easily compiled by those who 

 Bpend much time in dredging, tow-netting, etc. The algal '_rrowth> on the 

 bottoms of both large and small vessels present, moreover, an almost nnworked 



field. 



:'. Comparison with othee Areas. 



Ecui Ireland. — A comparisoD of the Holistic features of the east and west 

 of Ireland does not reveal so great a contrast as was expected. No special 

 accountofthe east-coast flora has been published, nor have I personally examined 

 any part of the shore, except the extreme north. Adams ('08, annotated copy ) 

 lists most of the Clare Island austral species for Leinster, and a considerable 

 number for Ulster also. There are. however, ten well-known and conspicuous 

 algae which have not yet been recorded for the east coast, but most of these 

 would probably be found in Leinster if carefully searched for. S.E. Leinster is 

 similar, as to its flora, to Munster ; and Ulster has a surprising number of 

 southern species, Belfast and Larne Loughs being at one time famous for 

 Nitophylla and other seaweeds which occur chiefly in the southern counties. 

 At the same time, it would be advisable to confirm such records as Bifucaria, 

 GaUithamnion tetrit um, and Schizymenia Dubyi. The real difference between 

 the east and west coast lies doubtless in the proportion of southern vegetation 

 present : plants which are common or frequent in Mayo and Galway being 

 probably rare or very rare in Co. Dublin. The luxuriant growth displayed by 

 such species as Lomcntaria clacellosa and Dasya arbuscvla is also a characteristic 

 feature of the west-coast vegetation. 



England and Scotland. — With regard to England, as already shown, the 

 Clare Island flora resembles that of Devon and Cornwall, but in England the 

 boreal element (represented by OaUithammion arbuscv.la, and Ptilota phunom) 

 is wanting, as are also several other northern species. Codium mucroaattun is 

 likewise entirely absent. Such plants as Acrothrix and Stictyosiphon adriat icv.s, 

 known at present in the British Isles only from Ireland, will probably be found 

 in England when our south-coast bays have been more thoroughly explored 

 by dredging. On the other hand, a few well-known and conspicuous species, 

 more or less frequent in Devon and Cornwall, have not been found in Ireland. 

 The most noteworthy amongst these are Puncture" crispata, Graeilaria 

 compres8a, Grateloupia JfUcina, G. dirkotoma, and Spyridia jilo mentosa , the last- 

 named being locally abundant in Great Britain, and extending from Sussex to 

 Anglesea. There are also other species, but these are of very rare occurrence. 

 The east coast of England is comparatively poor; more than two-thirds of the 

 species listed on p. 102 are entirely absent ; the remainder have been reported 



