594 Proceedings of ihe Royal Irish Academy. 



fi'om the descriptions given of them, and he never adopted them, but 

 continiied to name his new species as they occurred to him by the 

 old established generic name Jungermannia up to the last, though 

 he knew they belonged to genera established by modern authors. 

 Even the late Sir "William Hooker, who studied the British Junger- 

 mannia with a rare discriminating power, did not attempt to divide 

 the old genus Jungermannia, but was content to place the species in 

 natural groups, which are pretty much the same as those now adopted, 

 several of them being represented by modern genera. His great work 

 on the British Jungermannia is, indeed, one of the most beautiful and 

 most exhaustive ever written on any subject of natural history. In 

 the present Eeport, I have adopted Dr. Lindberg's arrangement, both 

 for the sake of uniformity, and because I consider it the most 

 natural yet published. 



Ireland is extremely rich in this family of plants, and produces a 

 number of remarkable species, which are true indicators of the- 

 climate of the country. These minute vegetables, some of which are 

 scarcely visible to the unaided eye, tell of heat, moisture, and other 

 climatal circumstances, much more accurately than the flowering plants 

 of the country do, and show that the south-west of Ireland approaches 

 in climatal conditions some sub-tropical parts of the world. 



In a letter from the well-known traveller. Dr. Spruce of "Wel- 

 burn, Yorkshire, who has explored a very large portion of South 

 America, collecting both the flowering and ciyptogamic plants of that 

 country, he states that ' ' when gathering mosses and Hepaticae on the 

 slopes of the Ancles, he was reminded of the Kerry Mountains, whose 

 cryptogamic vegetation is the nearest approach in Europe to that of 

 tropical mountains." Among the species most characteristic of a 

 warm and moist climate, I may mention particularly Dumortiera 

 irrigua, Eadula xalapensis (Radula voluta, Taylor), found also in JS^ew 

 Granada, Metzgeria linearis, which grows also in Jamaica, and Gruada- 

 loupe, EruUania Hutchinsise, variety /?., in the Island of Java, and 

 the minute Lejeunise. Among the mosses we have the beautiful 

 Hookeria Itetevirens, which occui's in the "West Indies, besides the 

 Killarney Eern (Trichomanes radieans), another plant which extends 

 to the West Indies. 



I have spared no trouble to ensure correctness in the names of the 

 plants, for which purpose I have frequently consulted both Dr. Car- 

 rington and Professor Lindberg, who have always very kindly assisted 

 me with their opinion. 



The Irish habitats may be relied upon, as I have collected nearly 

 every one of the plants with 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 the sea-level to the tops of the highest mountains. 

 The chief merits of this Report may indeed be considered to consist in 

 its giving as full an account as I am able to render of the Irish Hepa- 

 ticse, and of their geographical distribution in Ireland. 137 species 

 of them are enumerated. 



