FISSIDE^S SERRULATUS. 

 By H. Boswell. 



Bkyological readers of the Naturalist who may happen to visit the 

 western coasts should keep a look-out for this handsorue moss, lately 

 found for the first time in Britain by Mr. Curnow. It is not impos- 

 sible that it may grow by the side of some rocky stream between 

 Carmarthenshire and the Hebrides, or in the south and west parts of 

 Ireland. Long supposed a native only of Madeira and the neigh- 

 bouring islands, it was subsequently found in Portugal, and is one of 

 a few mosses of sub-tropical character and affinities, whose presence 

 with us is doubtless due to the influence of the Gulf stream; such are 

 Ulota calvescens, Daltonia splachnoides, Hookeria locte-virens, Myuriiim 

 Sehridarum, &c. ; and where they grow, F. serridatiis may also occur 

 if fitting habitat be found. 



Mr. Curnow has occasionally, during the last twenty years, sent me 

 specimens of JE. polypJiyllus, and during last November sent me two 

 more, of somewhat different aspect, together with a third plant which 

 he thought seemed different from either ; and so it was, and-' from 

 any that he had forwarded before, nor had I much hesitation in 

 coming to the conclusion that it was unmistakeably P. serrulatus — a 

 very interesting addition to our British flora. 



There is sufficient resemblance between the two to make it very 

 possible to pass over F. serrulatm as pohjpJiylhis, unless the attention 

 is awake ; yet there is plenty of difference between them when closely 

 examined. In F. pjolypJiyllus the leaves taper gradually to a point ; 

 they are without border, entire except at the apex, which is serrulate ; 

 the cells at the basal part are gradually enlarged from the margin 

 inwards towards the nerve, those of the long-decurrent angles being 

 linear-oblong, thin and hyaline ; the male flowers are eight or nine- 

 leaved. In F. serrulatus the leaves are not tapering, but straight in 

 outline and obtuse-pointed, the margins of the conduplicate portion 

 finely serrulate, the apex of the lamina serrated, and they are 

 furnished with an evident border of yellowish-coloured cells, some- 

 what larger than the rest ; while the basal cells are uniform, and the 

 male flowers three-leaved. 



When the " Bryologia Britannica " was published, little was known 

 of this species and its allies : and Wilson, with a commendable desire 

 to avoid the needless multiplication of species, united his pnlypJiyllus with 

 N. S., Vol. v.— April, 1880. 



