190S. Ada^is. — Irish Biological Sub-pj-ovinces. 147 



Holmes and Batters in their paper (6) on British Marine 

 Algae, published in 1890, divide the Irish coast line into five 

 districts : — (i) Malin Head to Slyne Head. (2) Sljme Head to 

 Crow Head. (3) Malin Head to Howth. (4) Howth to Raven 

 Point. (5) Crow Head to Raven Point. 



The same divisions of the coast line were adopted b}- the 

 authors of " Irish Phaeophycese," but the " Irish Coralli- 

 naceae" are grouped according to the counties for the most 

 part. 



Nichols, in dealing with the Marine Mollusca of Ireland 

 (16) in 1900, divides the coast line into the following six 

 divisions : — (I.) North-east — From Malin Head to St. John's 

 Point. (11.) East — From St. John's Point to Carnsore Point. 

 (III.) South— From Carnsore Point to Cape Clear. (IV.) 

 South-west— From Cape Clear to Loop Head. (V.) West — 

 From Loop Head to Erris Head. (VI.) North-west — From 

 Erris Head to Malin Head. He adopts the 100 fathoms line 

 as the limit of the shallow-water area. Nichols' six divisions 

 have also been adopted for the distribution of Irish Echino- 

 derms (17) and Coelenterates (22). 



Then, in Batters' Catalogue of the British Marine Algae (2), 

 published in 1902, the old divisions which were previously 

 emplo3'ed by him and Holmes are abandoned and the counties 

 used instead. 



Finally there are the 21 Fishery Districts into which the 

 coast-line has been divided. 



It will be clear from the above statements that there is a 

 very considerable difference of opinion as to the distributional 

 areas into which the country should be divided. Several 

 authorities adopt the four provinces, but the majority seem to 

 incline towards the counties or vice-counties, and the modern 

 tendency seems to be distinctly in favour of Praeger's forty 

 divisions— at anj'- rate for the land and freshwater species. 



The thought has often occurred to me that it would be 

 desirable to have a series of sub-provinces, intermediate in 

 size between Praeger's 40 counties and vice-counties on 

 the one hand and the four provinces on the other — a series in 

 fact corresponding in size to the 12 districts of Babington but 

 differing from them in the following particulars : — {a) Each sub- 

 province should consist of several of Praeger's 40 counties and 



A 2 



