M DTTBLIN NATT7BA1 HISTORY SOCIETY. 



usaal ontline of frond, confluent or distinct, never curled or crisped ; midvein 

 terminating in a point at apex of each segment : generally fruitful. Examples 

 of group — -Ph. scolopendrium, sub-variety 7nM//i/icfw7?i;Lomaria spicant, sub-va- 

 riety viuhifidum ; Ath. Filix fsemina, subvariety mullifidum. There can but one 

 form of this occur, and we can, hence, easily distinguish in description what axis 

 of the plant is affected, using X to represent the primary, and Z the secondary, 

 &c., axis; if thought proper, marking the divisions of the rachis as X 1, the di- 

 Tision of the stipe as X 2. The same divisions might also be made in the va- 

 riety ; but they are particularly well shown in the sub-variety {vide list). 



The form Z is most striking in compound fronds ; but even in simple fronds 

 something, to say the least, strongly analogous is to be found, at all events, in 

 the variety in a form of Phyl. scolopendrium, called endivifolium by its disco- 

 verer, Mr. Young ; and also, though in a less degree, in the form named undu- 

 latum or crispum, which is said to be merely a degenerated form of ramosum. 

 ( yide second part.) In Mr. Young's plant, we find the veins prolonged and 

 thickened, and almost converted into branches, rendering the fern multifid along 

 its edges. The same form is also seen in a more exaggerated state, in another 

 form, also forwarded to me by G. B. Wollaston, Esq. (thanks to whose kindness 

 I am enabled to illustrate this subject so well by specimens); he calls it Digita- 

 turn. In it we find regular midribs proceeding from the main midrib, and giving 

 the frond a regular branched pinnatifid appearance, yet manifestly but a modi- 

 fication of the ramose type. Indeed, for any one wishing to study these two forms 

 there can be no better species than Scolopendrium. 



The subvariety multifidum is, as might be expected, found in many foreign 

 genera and species. I show specimens of Mohria thurifraga, and an exotic As- 

 plenium and Polypodium, thus affected. The system pursued in naming these 

 forms has been, when practicable, adopting the name given to the forms when 

 first described, choosing the most typical. These were, in the two classes, con- 

 sidered Phyll. Seol. cristatum, and multifidum. 



I lay before you a list of the species in which these two forms occur, with 

 their synonymes, as far as I have been able to trace them, so that you can judge 

 of the extent of them for yourselves ; many other species, doubtless, will be 

 found to partake of these characters when the subject is more attended to. I 

 also show you specimens of many of them, mostly gathered by myself, and hope, 

 at a future meeting, to state a few more facts connected with the subject, and 

 to bring before you other classes which are as well defined as this. 



LIST OF SPECIES OF BRITISH FERNS. 



Variety Cristatum, and Sub-variety Multifidum. 

 [Explanation of Marks — Species in brackets, not recorded as Irish thus, 

 [(Woodsia)]. Marked thus, (?) I am in doubt concerning. X 1 shows rachis 

 divided ; X 2, stipe, do. do ; Z, pinnae, or pinnules.] 



Adiantum Capillus Veneris (Linnseus). 



X 2, cultivated plant; G. B. Wollaston, Esq. 

 Eupteris aquilina (Newm.); sub-var. multifidum (Mei) ; Phyt., 1853, p. 1036; 

 X 1 and 2, scarce ; Z, rare (a diminutive specimen from top of Three-rock 

 Mountain, county of Dublin, has rachis divided to within half an inch of 

 ground). Not very uncommon about Ballinteer, in this county. 

 England: G. B. Wollaston, Esq., Epping Forest (Kin.). 

 Lomaria spicant (Desv.) ; sub-var. multifidum (Mei); Phyt., 1853, pp. 892 and 

 1036. X 1 and 2, rather rare ; Z, rare. Clare and Dublin ; very fine at 

 foot of Great Sugarloaf, county of Wicklow; generally grows in moist si- 

 tuations. 

 Kerry: W. Andrews, Esq. 



England. Figured Deakin, Fl. Br., p. 52. Very fine specimens of Z for- 

 warded me by G. B. Wollaston, Esq., as bifidum. Jersey, M. Piquet. 

 Phyt. ia53, p. 1135. J ^ 



