FISSIDENTACE^.] 80 [Fissidetis. 



slender, unequal, nodulose legs; perich. bracts about 5, ovate, sheathing, 

 with an elongated sword-shaped lamina. Male plant about 2 in. high, 

 with longer leaves, the infl. axillary, numerous, 8-leaved, outer bracts 

 small, ovato-lanceolate, inner from an obovate base, suddenly passing 

 into a narrow, linear, nerved, flexuose lamina, antheridia large, numerous, 

 with few paraphyses. 

 HAB. Wet shady rocks. 



Glengariff, Ireland (Wilson 1829) ! Pont Aberglaslyn on the right of the road to 

 Tremadoc, N. Wales (Wilson 1838) ! ! Well and river side at Treveylor, Penzance 

 (Curnow 1866) ! ! Banks of the Dart, Holne bridge, S. Devon (Marqnand 1884). 



This fine moss was first distinguished by Wilson, but afterwards he 

 referred both it and F. serrulatus to the West Indian F. asplenioides SWARTZ. 

 The very interesting discovery of the fruit has confirmed its distinctness, and 

 I am indebted to the kindness of M. Husnot for the opportunity of figuring 

 a specimen, though, unfortunately, without operculum. It was found in the 

 " Breche de Toul-an-Dioul," near St. Rivoal, Dep. of Finistere by M. Camus 

 in June, 1878. A form occurs in the Beddgelert locality with the leaves 

 somewhat falcato-secund. 



Since the above monograph was issued, an important paper by Mr. Mitten 

 has appeared in Journ. Linn. Soc. Bot. XXI, 550 (1885), which adds con- 

 siderably to our list of species, and alters many of the older views. This 

 necessitated a fresh study of these mosses, and as Mr. Mitten has kindly 

 supplied me with most of his types, I have taken the opportunity of drawing 

 them on an additional plate and again enumerating our species, with remarks 

 where my conclusions differ from those of the talented author. A good paper 

 on the American species, by Mr. C. R. Barnes, of Purdue University, Lafa- 

 yette, has also appeared in the Botanical Gazette for January and February, 

 1887. It must be remembered that the optical aids to examination at the end 

 of last century were of a very primitive kind and limited in use, hence we 

 need not be surprised that among the minute sorts, various species were dis- 

 tributed under the same name, because there were no means of certainly 

 distinguishing them, hence we think too much stress must not be laid on her- 

 barium specimens as types of species. 



The principal characters in Mr. Mitten's arrangement are, i. the position 

 of the male inflorescence, 2. the erect symmetric, or inclined unequal cap- 

 sule, -3. the presence or absence of a hyaline limb to the laminae of leaf. 

 Among the small species of Fissidens, and in some of the larger, we have 

 come to the conclusion that the position of the inflorescence is most variable, 

 and affords no stable specific character, as indeed Mr. Mitten states, though 

 the key conveys a different impression ; nor is much value to be attached to 

 the erect or inclined position of the capsule, for both certainly occur in the 

 same species, though the symmetric or asymmetric form, if well marked, may 

 prove more reliable, but with respect to the limb bordering the leaves, we 

 attach more weight to it, as constituting a character of importance in the 

 structure of the leaf, and undoubtedly of great value in discriminating species 

 of such genera as Mnium and Bryum. 



