Ser. MelaxospermejE. Fam. Biciyotacece. 



Plate XXXIV. 



LOBOSPIRA BICUSPIDATA, Aresch. 



Gen. Char. Stem with a branching root, cartilaginous, compressed, alter- 

 nately branched; branches costate below, linear, pinnatifid, the seg- 

 ments bicuspidatc. Scores scattered over the surface of the segments, 

 prominent, each contained in a hyaline perispore. — Lobospira 

 (Aresch.), from Xoftos, a lobe, and cnreipa, a tvnst ; from the spi- 

 rally twisted branches of the only known species. 



Caulis basi radicans, cartilagineus, teretl-compressus, alterne ramosus ; rami 

 in/erne costati, linear es, pinnaiifidi, lacinulis bicuspidatis. Spores per super- 

 ficiem laciniarum sparsae, prominentes, intra perisporum hyalinum singula 

 niduluntes. 



Lobospira hicuspidata, Aresch. 



Lobospira bicuspidata, Aresch. Phyt. Nov. p. 38 (Jide Sond. in lift.). 



Metachroma thuyoides, Harv. in Trans. R. I. Acad. v. 22. p, 535 ; Alg. 

 Austr. n. 75. 



IIab. On sand-covered rocks, about low-water mark. Fremantle, Western 

 Australia, G. Clifton. Middleton Bay, K. G. Sound, and Cape Kiche, 

 abundantly, IV. H. H. 



Geogr. Distr. Western Australia. 



Descr. Root fibrous, much and diffusely branched, deeply descending into the 

 sand, or grasping on neighbouring objects. Fronds tufted, 6-18 inches 

 high, much branched, and bushy, the branches directed to all sides. Stem 

 cylindrical or somewhat compressed, especially in its upper part, cartila- 

 ginous, about as thick as small twine, generally continued undivided through- 

 out the frond, sometimes forked, closely set throughout with patent lateral 

 branches. These branches are 2-4 inches long, slender, flat, furnished with 

 a midrib which is strongly marked in the lower half of the branch, and gra- 

 dually fades away towards the summits, and are alternately or subdichoto- 

 mously divided. The ultimate divisions are linear, spirally twisted, and al- 

 ternately pinnatifid ; the pinnules not the tenth of an inch in length, bicus- 

 pidate or sharply bidentate, with rounded axillae. The membrane is areolate, 

 with quadrate cells, which converge towards the apices of each terminal 

 tooth of the pinnule. The spores (or antheridia ?) are hemispherical, and 

 form diffused sori on each pinnule of fertile specimens. The substance, 

 when growing, is crisp, brittle, and somewhat cartilaginous; when dry it is 

 rather rigidly membranous, and the frond does not adhere to paper in 

 drying. The colour, when growing, is a clear greenish-olive, but on expo- 

 sure to the air or immersion in fresh-water it rapidly changes to bright ver- 

 digris ; the olive, but darker in tone, returning in the dried specimen. 



