NOTES ON BRITISH HEPATICjE 261 



appear to have always more than one row of cells, and one or more 

 always winged and frequently dentate. The wing varies in size, 

 but is often composed of a single series of 6-9 cells superimposed 

 on an angle thickened to the extent of several layers of cells. 

 The mature bracts and bracteole are nearly always less deeply 

 divided, and with the cuspidate points shorter than in L. cuspidata, 

 and form, in my opinion, a more valuable distinctive mark than 

 does the perianth alone. The bracteole is by no means always 

 oval as in Mitten's figure. It varies considerably in shape, and not 

 rarely has a tooth on one or both sides, but it is nearly always less 

 deeply lobed than in L. cuspidata. Mitten is evidently mistaken in 

 giving the leaf-cells as twice the size of those of L. bidentata. They 

 do not appear to be larger than in L. cuspidata. The plant is 

 generally dark green, and with the leaves rather broader than in 

 the most commonly pale- coloured L. cuspidata, but this is not a 

 reliable distinction. 



I sent a small specimen of the North Devon plant to Prof. 

 Schiffner. He remarked on the variation of its characters, and 

 that the mouth of the perianth was similar to that of L. cuspidata, 

 of which he considered it to be only a form. He also stated that it 

 had no relationship to L. coadunata. It appears that more than 

 one species has been described as Swartz's plant, and it is probable 

 that Mitten had not seen the true plant of Jamaica. The descrip- 

 tion of this by Herr Stephani in the recently published part of Spec. 

 Hep., p. 146, does not at all correspond with L. alata, and it is men- 

 tioned that the plant which Spruce gives under Swartz's name does 

 doubtless not belong to it. I sent a specimen of L. alata to Herr 

 Stephani, but am doubtful if he considers it a distinct species. 



Considering that the characters which distinguish L. alata from 

 L. cuspidata are subject to considerable variation, and that such 

 differences are only one of degree, I think that the former can 

 hardly be regarded as of specific rank. I should feel inclined to 

 look upon it as a subspecies of the latter. However this may be, 

 in all the specimens which I have seen of both plants from various 

 localities, I have rarely found any difficulty in distinguishing 

 between them. Their distribution in Britain is also different. 

 L. alata is more common than L. cuspidata, and to some extent 

 takes the place of it, in some parts, at least, of the south of 

 England, but becomes much rarer than the latter as we proceed 

 northwards. It is evidently rare in Scotland, and has only been 

 found, so far, in the southern counties. On the other hand, 

 L. cuspidata is common and widely distributed throughout nearly 

 the whole of the low-lying parts of Scotland. 



L. bidentata (L.) Dum., is dioicous, and seems rarely to be 

 found with perianths in Britain, 



I have seen specimens of L. alata from the following localities : — 

 Sussex: several localities, 1905-1907, W. E. Nicholson. Cornwall : 

 Castle Horneck, Penzance, April 1, 1907, W. E. Nicholson. North 

 Devon : Berrynarbor, 1907, Miss C. E. Larter. Somerset : near 

 Failands, March, 1907, Miss A. Fry. Stafford: near Armitage, 

 March, 1900, H. P. Reader. Pembroke : St. Ishmael's, January, 



