McArdle — A Lid of Irkh Repaticie. 389 



my own hands at some time or other during the last forty years, 

 having for this purpose travelled over a very large portion of Ireland, 

 from east to west, and from north to south, and from sea-level to the 

 tops of the highest mountains. The chief merits of this Report may 

 indeed he considered to consist in its giving as full an account as I 

 am ahle to render of the Irish Hepaticae, and of their geographical 

 distiihution in Ireland; 137 species of them are enumerated." It 

 will be seen from the following list that I have endeavoured to 

 follow closely in the footsteps of this great bryologist, and have 

 availed myself of every advantage o:ffered to further the object. I 

 enumerate 172 species and sixty-three varieties; some of the latter 

 have been raised to the rank of species by authors, and they are all 

 more or less of botanical value. To Mr. W. H. Pearson, of Manchester, 

 and Mr. M. B. Slater, of Malton, Yorkshire, I offer my best thanks for 

 their help in matters of doubt when investigating critical species. 



Physical Features. 



The physical features of Ireland are favourable for the growth of 

 Hepatiese. A large area is occupied by peat bogs both lowland and 

 mountain ; and large lakes lie in the central plain, with smaller and 

 more numerous ones towards the west — as in Connemara,West Mayo, 

 and Kerry, In the north-east, Lough Neagh covers an area of 153 

 square miles, and is the largest fresh-water surface in the British 

 Islands. The Shannon is the largest river; it flows for 214 miles, 

 and creates in its course Lough Ree and Lough Derg. The eastern 

 part of the central plain is drained by the Rivers Boyne and Lifiey, 

 the south-eastern' part by tlie Rivers Suir, Barrow, and Nore ; while 

 the waters of the north-eastern part are collected into Lough Neagh, 

 chiefly by the Blackwater, and from thence discharged into the sea 

 by the Lower Bann. The rivers outside the central plain are short ; 

 the principal ones are the Erne, flowing north-west ; the Foyle and 

 Bann to the north ; the Slaney to the south-east ; and the Bandon, 

 Lee, and Blackwater flowing through Co. Cork. The bays and 

 marine loughs are numerous and deep, penetrating inland for a con- 

 siderable distance, as Lough Swilly on the north coast, Bantry Bay 

 in tlie south-west, &c. 



The principal mountain ranges are near the coast. The liighest 

 Irish mountain is Carrantuohill, 3414 feet, which is part of Magilli- 

 cuddy's Reeks in Kerry ; while westward across the Ivi^ragh and 

 Dingle Peninsulas lies Brandon, which rises to 3127 feet, and is the 



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