(JHAr. XVI.] 



THE BRITISH ISLES. 



.^43 



six in India and Ceylon, five in Java, two in Africa, and three in llio 

 Antarctic Islands, and one in Ireland. 



HcoKEEiA (restricting that term to the species referable to Cyclodictyon) 

 is still a large genus of handsome and remarkable mossep, having twenty- 

 six species in the Andes, eleven in Brazil, eight in the Antihes, one in Mexico, 

 two in the Pacific Islands, one in New Zealand, one in Java, one in India, 

 and five in Africa^ — besides our British species, which is found also in 

 Madeira and the Azores but in no part of Europe proper. 



Tliese last two are very remarkable cases of distribution, since 

 Mr. Mitten assures me that the plants are so markedly different 

 from all other mosses that they would scarcely be overlooked in 

 Europe. 



The distribution of the non-European genera of Hepaticse is 

 as follows : — 



AcROBOLBUS. A small genus found only in New Zealand and the adjacent 

 islands, besides Ireland. 



Lejeunia. a very extensive genus abounding in the tropical regions of 

 America, Africa, the Indian Archipelago, and the Pacific Islands, reaching 

 to New Zealand and Antarctic America, sparingly represented in the British 

 and Atlantic Islands, and in North America. 



Petalophyllum. a small genus confined to Australia and New Zealand 

 in the southern hemisphere, and Ireland in the northern. 



We have also a moss — Myurium hehridarum — found only in Scotland and 

 the Atlantic Islands ; and one of the HepaticEB— J/a6•%o/J>/^«?•« looodsil — 

 found in Ireland and the Himalayas, the genus being most developed in 

 New Zealand, and unknown in any part of continental Europe. 



These are certainly very interesting facts, but they are by no 

 means so exceptional in this group of plants as to throw any 

 doubt upon' their accuracy. The Atlantic islands present very 

 similar phenomena in the HhampJiidimn purpuratum, whose 

 nearest allies are in the West Indies and South America ; and 

 in three species of Sciaromium, whose only allies are in New 

 Zealand, Tasmania, and the Andes of Bogota. An analogous 

 and equally curious fact is the occurrence in the Drontheim 

 mountains, in Central Norway, of a little group of four or five 

 peculiar species of mosses of the genus Mnium, which are found 

 nowhere else ; although the genus extends over Europe, India, 

 and the southern hemisphere, but always represented by a very 

 few wide-ranging species except in this one mountain group I ^ 



^ I am indebted to Mr. Mitten for this curious fact. 



