A NEW BRITISH MOSS 289 



although at the time I knew the latter only from descriptions and 

 from Braithwaite's figure. This resemblance I found had also 

 occurred to Limpricht, as quoted above. F. Orrii is supposed to 

 be an introduction from exotic regions, and was referred by Mitten 

 to his South American F* tequendamensis, a species which I have 

 not seen. The distribution of F. algarvicus, along the Atlantic 

 from Portugal and Spain to Finisterre and the southern shores of 

 England, would, indeed, favour Limpricht's suggestion. I am 

 doubtful, however, if this identity can be maintained. I have 

 examined the specimen of F. Orrii in the British Museum (Glas- 

 nevin, D. Orr, 1854, herb. S. 0. Lindberg), and while the close 

 similarity between this and F. algarvicus is undoubted, there are 

 points of difference which can scarcely be neglected. The nerve 

 in F. Orrii is much stouter than in F. algarvicus, and runs out into 

 a firm stout mucro, as figured by Braithwaite ; in F. algarvicus the 

 nerve usually becomes more or less evanescent at apex, and the 

 cuspidate point is formed almost entirely by the confluent borders 

 of the leaf. In consequence of the stoutness of the nerve, the 

 leaves are still more rigid, and when dry less altered than in 

 F. algarvicus. The capsule also in F. Orrii is inclined and curved. 

 I do not feel justified, therefore, in considering F. Orrii identical 

 with F. algarvicus, although I think it quite probable that the 

 examination of a wider range of material might show that the 

 above characters were less constant than they now appear, and the 

 differences therefore less important. I am the more prepared to 

 expect this because I find the areolation in F. Orrii quite similar 

 to that of F. algarvicus, especially in the unusually lax and elon- 

 gated cells of the vaginant lamina. 



On the other hand, F. Sardagnai Vent, is, I am convinced, 

 identical with F. algarvicus. Although I have not seen specimens 

 of F. Sardagnai, the description given by Venturi is sufficiently 

 detailed to justify an opinion being formed. The size of the spores 



(in F. algarvicus 11-14 /x, in F. Sardagnai 15-20 /x) and their 



sculpturing are the chief separating characters mentioned by Ven- 

 turi. The difference in size is not, however, of any importance, 

 for, apart from the fact that a similar range of size is found in other 

 species of Fissidens (e. g. in F. pusillus the spore measurements, as 

 given by Koth, are 8-12 /x or 10-14 /x, while its var. irriguus Limpr. 

 has them 14-18 /x), the range in F. algarvicus is much greater than 

 as described by Venturi. In two gatherings by Mr. Savery I find 

 them range from 13-18 /x, and from 14-22 /x respectively. As 

 regards their sculpturing, Venturi describes the spores of F. Sar 

 dagnai as " leniter sed grosse papillose M ; in F. algarvicus they ar< 



smooth or almost so : but it is somewhat difficult to weigh the 

 value of this distinction without having compared specimens. The 

 description by Venturi of F. Sardagnai applies as a whole in almost 

 every respect to F. algarvicus; the form of leaf, the incrassate 

 border — on which he lays great stress — the lax areolation, all 

 exactly agree. He compares his species with F. algarvicus, 

 which, however, it is clear he only knew from the descriptions, 

 basing the distinction on the size and sculpturing of the spores, 





