Dr. Greville on some new species of Sargassum. 503 



There is also a section of Jungermannia, consisting entirely of 

 exotic species, which approaches Southhya, though more remotely. 

 The type of this section is Jg. turgescens, Tayl. et Hook. fil. in Crypt. 

 Antarctica, p. 38, t. 64, which has the perianth slightly compressed 

 laterally and truncate, but quite discrete from the involucre. The habit 

 too is widely different, the stems being much divided, scarcely radicu- 

 lose, the leaves very concave, with a minute guttulate areolation (the 

 cellules round, separated by wide interstices), and there are bifid 

 stipules present. Alicularia strongylophylla, Eorund. /. c. p. 34, t. 62, 

 has the perianth exactly as in Jg. turgescens, quite free and sometimes 

 twice as long as the involucre ; the chief differences being the less con- 

 cave leaves and the wider areolation (yet still equally guttulate) : it 

 is therefore not an Alicularia, and with Jg. turgescens might well 

 constitute a new genus, of which other species are probably Jg. cequata 

 and humilis of the same authors. Possibly their Alicularia occlusa 

 and the Jungermannia Liebmanniana of Lindenberg and Gottsche may 

 go into the same genus, but of these I have not seen specimens. 

 These species seem all intermediate between Southbya and the true 

 Jungermannice, which they approach through Jg, Taylori and its 

 allies. 



On another side, Southbya has some affinity with a small group, 

 of which Jungermannia hyalina is the European representative ; but 

 these differ from it in the red radicles, and in the perianth being con- 

 tracted and numerously plicate towards the mouth. 

 [To be continued.] 



XLI K. Algce Orientales : — Descriptions of new Species belonging 

 to the genus Sargassum. By R. K. Greville, LL.D. &c.* 



[Continued from p. 257.] 

 [With a Plate.] 



At the moment when I have brought these descriptions of Sar- 

 gassa to a close, I have learned that the first volume of the ' Ge- 

 nera et Species Algarum ' by the younger Agardh, has appeared. 

 This I was, of course, unprepared for, having never, in fact, even 

 seen the work advertised. I would gladly have deferred bring- 

 ing forward my present series of papers until I could have had the 

 benefit of consulting that work, but it is now too late, and some 

 confusion in nomenclature will be the probable result. It will be 

 remembered that in commencing these descriptions I stated, that 

 with few exceptions the subjects had been transmitted to me by 

 my friend Dr. Wight for publication in the second volume of 

 the 'Prod. Fl. Ind. Orientalis,' and that the interruption which 

 had occurred in the continuation of that undertaking had in- 

 duced me, after retaining my notes and drawings for many years, 



* Read before the Botanical Society of Edinburgh, April 12, 1849. 



