178 DUBLIN NATimAL HISTOET SOCIETY. 



with the sporangia, arising from the base or axis of the the slit or groove, 

 pointing upwards, distinguishing the genus from Tseniopsis, which is 

 characterized by the sporangia being produced in a similar groove, 

 but which is situated on the disk within the margin of the frond. I do 

 not, therefore, consider that the reference to Ceratoptcris, or to the common 

 Hart's-tongue, has any analogy bearing upon the point of discussion. 

 In a conversation with the distinguished Robert Brown on the character 

 of the Trichomanes of Glouin Caragh, in Kerry (a man of whom Sir 

 Robert Peel observed, ** his retiring modesty and unpretending merit 

 were the index of a great and talented mind"), that first of botanists as- 

 sured me that it was the type of the European form, and that it established 

 its identity with Trichomanes radicans of Jamaica. It was the clime, 

 from its western position, and influenced by the broad Atlantic, that gave 

 such luxuriance of growth and such copiousness of fructification; and he 

 smilingly observed, '* I do not know how I fell into the error of naming 

 itBrevisetum." The Glouin Caragh plant was the normal European state 

 of that fern. Sir William Hooker, in writing to me on the same subject, 

 expresses — " It is an honour to your country to have a West Indian 

 plant growing there, and tells volumes in favour of the mildness of the 

 climate." 



The same may be applied to the two species of Hymenophyllum of 

 Kerry : they are the types of the European forms of that genus, and are 

 specifically distinct in aspect and habit. I consider those of the Continent 

 to be but mere sub-forms, apparently running into each other ; but I 

 should like botanists to prove that they can show the distinct foi-ms and 

 characters of the involucres of Tunbridgense and of Wilsoni existing 

 together on the same frond. Mr. Wilson observes to me that his Welsh 

 specimens of H. Wilsoni are pigmies compared with those obtained from 

 Killarney. The Adiantum capillus- Veneris of the Aran Isles, and of 

 Burren, in Clare, is identical with the forms of Madeira and of the Ca- 

 nary Isles, which were tenned Adiantum Africanum by Robert Brown, in 

 his Appendix to ''Tuckey's Voyage." These forms are monstrous when 

 compared with the stunted growth of those of Cornwall and of the south 

 of Europe, and even of those which have been noticed in wells and in 

 moist caves in the neighbourhoods of Rome and Naples (the specimens 

 exhibited from Cremleigh Point, in Clare, and from Aran, were eigh- 

 teen inches in length). The Hymenophyllum Boryanum, discovered by 

 Bory St. Vincent in Bourbon, of which I submit beautiful specimens, is 

 very similar in outline and reticulation of pinnae to Tunbridgense ; but 

 it difiers materially in aspect in the hairy underneath part of the 

 frond, and in the branched hairs at the margins (which seem very cha- 

 racteristic of exotic species) ; the involucres are suborbicular, ciliated, 

 and sunk in the frond. It is closely allied to H. ciliatum of Brazil, but 

 specifically separated by the different character of the involucres. Again, 

 referring to Willdenow (p. 519) what distinction can be shown between 

 H. hirtellutn and JL ciliatum, but merely in the more ovate form of the 

 frond and in the differently shaped involucres ? Hymenophyllum unihria- 



