502 INTRODUCTION TO CRYPTOGAMIC BOTANY. 



not, however, in general a plant of flat countries. A few 

 species only are Eurojjean. Authors, indeed, are by no means 

 agreed as to the limits of the genus. Within the above 

 definition, by which H. lueens and loete-virens are included, 

 numerous species occur in New Zealand and Australia, 

 including Tasmania, and in other southern regions. The 

 calyptra is always mitriform, but occasionally it is deeply 

 ciliate at the base. A few species, as H. rohusta, are among 

 the larger mosses. H. nigella is remarkable for its dark 

 dingy hue. Two or three of the species included in the 

 Antarctic flora have erect sporangia, but are separated from 

 Leiicodontei by their mitriform calyptra. Many forms occur 

 in other parts of the world, and in very different climates, 

 but till the genera and affinities are more settled it is difficult 

 to sjDeak of individual species. In any arrangement it must 

 be remembered that habit is of more consequence than the 

 peristome ; but even this must not be attended to, to the 

 exclusion of evident affinities, while mere analogues are placed 

 in close connection. The association of the white mosses, 

 called by authors Leucohryacew, with Sphagnei is an instance 

 of this kind ; but though the leaves agree in colour, and in 

 some points of structure, the fruit is totally unlike, so that 

 nothing can be more unnatural than their juxtaposition. 



7. Neckerei, Mont. Omalie^, Br. dc Sc. 



Stem mostly compressed and pinnate ; peduncle usually 

 short or wanting ; peristome double ; calyptra dimidiate. 



561. The pinnate branching is the most striking distinction 

 of these plants from Hookeriei, from which they are moreover 

 separated by the cuculliform calyptra, which is frequently 

 pilose. The species are perennial, and many of them are 

 amongst the most elegant cryptogamic productions. The 

 foliage is often undulated, and the sporangium sunk in the 

 perichcetial leaves or shortly pedunculate. Omcdia contains 

 such Hypna as H. trichoTnanes, with flattened pinnate or 

 subpinnate stems, and has unequal cernuous sporangia with 

 an inner peristome destitute of intermediate cilia between 

 the divisions, as in Leskea; while in Neckera the sporangium 

 is straight and erect. A few species only are European. 



