Ser. liHODOSPERMEiE. Fam. RkochjmeniaceeB. 



Plate CXXII. 



ACROPELTIS ELATA, Harv. 



Gen. Char. Frond stipitate, flat, imperfectly midribbed below, dichotomo- 

 pinnatifid, distichous or proliferous; composed of three strata; the 

 medullary of very slender, longitudinal, closely packed filaments ; the 

 intermediate of roundish angular cells; the cortical of minute, verti- 

 cally seriated, coloured cellules. Fructification : ^ , cystocarps . . .?; 

 2, shield-like nemathecia, in the tips of the branches, containing cru- 

 ciate tetraspores. — Acropeltis {Mont.), from aKpo^, the summit, and 

 TreXrT], a small sldeld ; alluding to the shield-like, terminal nema- 

 thecia. 



Trans stipitata, i^lana, inferne obsolete costata, dicJiotomo-pinnatifida, dictlcJia 

 V. prolifere ramosa, ex straits tribus formata ; stratum medullar e ex fills tenuis- 

 simis creberrimis lougitudinalibus, intermedium celluUs rotundato-angulatis, 

 corticate cellulis minimis coloratis verticaliter seriatis constitutum. Fructus : 

 1, cystocarpia ignota ; 2, nemathecia convexa, clypeifurmia, infra apicem fron- 

 dis evoluta, tetrasporas cruciatim divisasfoventia. 



Acropeltis elata ; very tall, and much divided ; stem elongate, piano- 

 compressed, channelled when dry, branched ; branches prolonged into 

 multipartite, dichotomo-pinnate, rigidly membranaceous fronds ; rachis 

 flexuous ; segments narrow-linear, dichotomous, erecto-patent ; apices 

 obtuse ; axils rounded. 



A. elata ; /;'o«(:/e longissima multipartita ; caide elongato plano-compresso costato 

 siccitate siibcanaliculato ramose ; ramis in frondes pergamenas inferne subcor- 

 datas dichotomo-pinnatas abeuntibus ; rachidefiexuosa ; laciniis alternis anguste 

 linearibus dichotomis erecto-patentibus ; apicibus obtusis ; axillis rotundatis. 



Ehodymenia elata, Harv. in Trans. R. I. Acad. v. 23. p. 554; Alg. Austr. 

 Exsic. n. 378. 



Hab. South coast of Rottnest Island, near the lighthouse, W. H. H. 



Geogr. Distr. Western Australia. 



Descr. Root a small disc. Fronds 2-2|^ feet high, very much divided, and the 

 old fronds irregularly proliferous. Stem 6-8 inches to a foot long, 1-1^ 

 line wide, thickened or ribbed in the centre, irregularly branched. Branches 

 3 2-14 inches long, alternately bi-tripinnate, the pinnse and pinnules sub- 

 dichotomous, flexuous, the older ones imperfectly costate, all preserving 

 nearly an equal breadth of 1-H line. Margin quite entire, slightly thick- 

 ened. Apices obtuse, either rounded or emarginate. Nemathecia placed 

 immediately below the apices, conforming to the shape of the apex, con- 

 vex, containing cruciate tetraspores. Colour a clear, full red, inclining to 



