Or THE ATLANTIC ISLANDS. 9 



from that of L. tamariscina, but only in the non-development of 

 those parts of the internal peristome which are present in that 

 species, and that the group of Leskece with erect capsules and 

 imperfect peristomes is precisely analogous to Pylaiesia and 

 Homalothecium, Schimp., — Pylaiesia having just the same position 

 with regard to Stereodon cupressiformis, Brid., and Homalothecium 

 to Hypnum rutabulum, Dill. In Hypnum Mspidum and in L. 

 prolixa the peristome is fully developed, and the habit approaches 

 to that of Thuidium ; but the stems and branches are destitute of 

 the phyllidia so general amongst Leskeoid mosses, and the cells of 

 the leaves are but very slightly papillose. M. C. Muller places 

 Hypnum Mspidum by the side of H.fluviatile, Sw. ; but the habit 

 and capsule are different, and the substance of the leaves more 

 rigid. Besides the H. Mspidum, there is in New Zealand another 

 species belonging to the same group, Leskea umbrosa, M. ; but 

 little can be said of its habit, for small specimens only have yet 

 been seen. Hypnum nervosum, Hooker, and H. crispulum, Dzy. 

 et Molk., appear to be possessed of the same habit, but are much 

 less. In time other species may be discovered, which will either 

 confirm the position of the group in Leskea, or perhaps show them 

 to be some modification of Hypnum with a dense areolation. 



HEPATIC^. 



Lejettnia, Dumort. 

 L. Johnsoniana, sp. uov. Caule repente vage ramoso, foliis diver- 

 gentibus orbiculari-ovatis angulo parvo acutis, basi lobulo subsaccato 

 inflexo oblongo apice bidentulo, amphigastriis orbiculari-obovatis 

 integerrimis, perianthio compresso obovato obtuso, ore parvo apicu- 

 lato, utrinque ala dentata marginata, foliis involucralibus elliptico- 

 oblongis apice paueidentatis, amphigastrio majore obtuso. 

 Hab. Madeira, creeping on Madotheca Canariensis, Nees, Johnson, 1859. 

 Whole plant brown, about the size of L. serpyllifolia, Lib., but 

 agreeing in the form of its perianth with L. (JPJiragmicomd) 

 Machaii, and thus removed from the vicinity of the species which 

 are allied to L. subfusca, Nees, with which it agrees in the form 

 and substance of its leaves as well as in size and colour. 



EXPLANATION OF THE PLATES. 

 Plate I. 

 Leskea spinosa. Plant, natural size ; leaf, magnified. 



Leslcea prolixa. a, Plants, natural size, b, Leaf; c, pericheetial leaf; d, cap- 

 sule ; e, portion of peristome : all magnified. 

 Leskea setigera. Plant, natural size ; leaf, magnified. 



