142 Bibliographical Notices. 



as a character to distinguish this plant from its near allies. The 

 Lastrcea spinulosa, L. dilatata, and L. cemula of authors are con- 

 sidered as one species, under the name of Nephr odium spinulosum. 

 It certainly seems to us that they form three well-marked species, 

 of which good plates are here given. A plate of L. dumetorum 

 seems unnecessarily introduced ; for it is surely nothing more than a 

 voung state of L. spinulosa : it here figures as a variety, on an 

 equality in rank with the three above-named plants. Some remarks 

 upon L. uliginosa would have been acceptable ; for it is one of the 

 most obscure of our plants, and the mature opinion of Sir W. Hooker 

 concerning it would have been highly valuable ; but it is passed over 

 almost without notice. Whilst combining these three well-marked 

 plants, as we think them, our author doubtfully separates, as a spe- 

 cies, the L. remota. If it is true that hybrids occur in Ferns, we 

 should be inclined to consider L. remota as one, having for its parents 

 L. spinulosa and L. Filix-mas. If our information is correct, very 

 few plants of it have been found. 



Cystopteris alpina is another plant which might well have been 

 omitted ; for certainly it has no claim to be considered as a native 

 of this country. 



Hymenophyllum Wilsoni is very properly kept separate from H. 

 Tunbridgense, and also from H. unilaterale. We are unable to under- 

 stand the difficulty which some persons seem to find in distinguish- 

 ing the H. Tunbridgense from H. Wilsoni. As our author most justly 



remarks, "It is hardly possible to see the two kinds growing 



frequently on the same rock, in separate patches, yet maintaining 

 their respective characters, without being satisfied of their being 

 really different." 



The figure of Isolites lacustris is by far the best that we have seen. 

 It represents the larger spores in a highly satisfactory manner, and 

 so as to show the remarkable difference between them and the spores 

 of the J. echinospora, which latter plant we find recorded as a native 

 of Wales and Scotland in the new edition of Babington's 'Manual.' 

 In all probability, Sir W. Hooker knew nothing of the existence of 

 I. echinospora in Britain ; for we believe that it was first announced by 

 M. J. Gay in the ' Bulletin de la Societe Botanique de France,' either 

 late in 1861 or at even a more recent date. 



There is a beautiful plate of the Guernsey form of Isoetes Hystrix, 

 under the name of I. ' Duricei. We have the authority of M. Durieu 

 for stating that the Guernsey plant is I. Hystrix. It has fewer of 

 the singular persistent woody leaf-bases (phyllopodes) than are found 

 on specimens from Algeria ; but such is also the case with the J. 

 Hystrix of France. It is at once known by its comparatively smooth 

 (very slightly tubercled, " tres-finement reticules") macrospores — 

 the oophoridia of Hooker. These are well figured by Fitch, but are 

 erroneously described as " strongly granulated." We possess au- 

 thentic specimens of these plants, and are quite convinced that /. 

 Hystrix is the correct name of that which grows in the Channel 

 Islands : but our opinion is of no consequence ; for M. Durieu is the 



