ing the moistened achaenia of some Composites. In South American specimens of R. Magellanica the seeds are paler and generally angled or. compressed ; the vessels of the raphe are also seen entirely detached from the walls of the membranes and running quite free between them to the summit of the albumen covered with the inner membrane, which thus appears suspended in the cavity of the outer coat, like the seed of some Amaranthaceous plant attached to a long funiculus.
The R.grandiftora is the type of this genus, to which the name of Marsippospermum was given by Desvaux; but from that word denoting a structure in the seed foreign to this species, and not implying a character peculiar to any group of Junci, I have substituted that of Rostkovia, to include both these and the following. The very peculiar habit and appearance of the species, the singularly large and solitary flowers, unlike those of any Junctis, together with the elongated style and the disproportionate size of the stigmata, are characters peculiar to all these, and appear of sufficient importance to warrant the retaining them under a separate generic name. M. Kunth in his 'Enumeratio Plantarum' (vol. iii. p. 356) places the R. Magellanica near Juncus trifidus, L., a plant to which it has assuredly no affinity, either in habit, inflorescence, or structure of the capsule. The R. grandiflora the same author removes to another section, and arranges it (probably following Mr. Brown's suggestion) along with /. castaneus, Sm., biglumis, L., triglumis, L., and some others of more dubious affinity, in a group at the end of the genus.
2. Rostkovia gracilis, Hook.fil.; rhizomate valido repente, culmis erectis fastigiatis gracilibus, foliis solitariis elongatis basi squamosis et vaginatis filiformibus teretibus rigidis, scapis solitariis folio ter brevioribus, bractea infra-florali solitaria brevissima obtusa, perianthii foliolis longissime lanceolate- subulatis, capsula lineari-oblonga perianthio multoties breviore. (Tab. XLVII.)
Hab. Lord Auckland's group and Campbell's Island; amongst rocks and also in marshy places ; common at an elevation of 800-1200 feet.
Rhizomata caespitosa, intertexta, horizontaliter repentia, 3-4 unc. longa, valida, crassa, sub ^ unc. diametr., dura, lignea, per totam longitudinem et praecipue versus apices culmos perplurimos superne emittentia, reliquiis foliorum vetustorum ubique vestita, subtus fibrosa; fibris validis, elongatis, 1-2 unc. longis, descendentibus, cuivatis, diametro pennae passerinas, copiosissime fibrillosis. Culmi numerosi, fastigiati, erecti, stricti, teretes, basi squamosi et vaginati ; squama e vaginis junioribus explanatis formats?, striata?, nitidas, castanese; vagina 2-3, folium arete amplectentes.elongatae, l-l|unc. longae, teretes, striata?, fulvaev. pallide castaneae, basi brunneae, politae, vernicosae, ad apices rotundatae, mucronata?; mucrone plus minusve elongato, pungente. Folium solitarium v. rarius duo, erectum, filiforme, elongatum, |-1 pedale, gracile, teres, striatum, vix ^ lin. diametr., gradatim acuminatum, apice subpungente, pallide viride, politum, intus spongiosum, fasciculis 8-10 tubulosis intramarginalibus vasorum percursum. Scapus erectus, solitarius, gracilis, teres, 2-3 uncialis, folio bis terve brevior, infra fiorem paulo incrassatus. Flos solitarius, majusculus, erectus, |-1 unc. longus. Bracteola infra- floralis solitaria, parva, late ovato-oblonga, obtusa, membranacea, sub lineam longa. Perianthium angustum ; foliola longe lineari-subulata, gradatim acuminata ; exteriora subinaequalia, longiora, et paulo latiora, interne plana, supra medium concava, dorso carinata, medio pergamentacea, striata, castanea, nitida, marginibus late scariosis; interiora subsimilia sed breviora et angustiora. Stamina breviuscula, foliolis interioribus perianthii breviora ; Jilamenla brevia, latiuscula, plana, medio uninervia; antherce filamentis quadruplo longiores, lineari-elongatae; connectivo ultra apicem in unguem obtusum, subrecurvum producto; loculis parallelis, contiguis, rimis lateralibus dehiscentibus. Pollen flavum, obtuse tetragonum. Ovarium elongatum, ovato-oblongum v. subconicum, obtuse trigonnm v. prismaticum, in stylum gradatim acuminatum, uniloculare, pluriovulatum, staminibus brevius. Placenta nerviformes, 3-seriales, a valvis facile divulsae. Ovula plurima, ascendentia, biserialia, funiculis brevibus placentis adnexa. Stylus rectus, elongatus, validus, ovario aequilongus, superne subincrassatus. Stigmata 3, majuscula, erecta, basi confluentia, perianthio inclusa, filiformi-subulata, intus glandulis pellucidis obsita, dorso
