Ser. MelanospermEjE. Fam. Chordariea. 



Plate XLI.U). 



MYRIONEMA LECLANCHERII, ffarv. 



Gen. Char. Minute Parasites, consisting of a mass of short, erect, simple, 

 jointed filaments, which spring from a thin expansion formed of de- 

 cumbent, cohering filaments, spreading in patches on the surface of 

 other Algse. Spores oblong, affixed either to the erect, or to the 

 decumbent filaments. Myrionema (Grev.) — from pvplos, a thousand, 

 and vqixa, a thread. 



Myrionema Leclancherii ; patches orbicular, thin, and with few vertical 

 filaments toward the edges, convex with crowded filaments in the 

 centre ; spores on long pedicels affixed to the decumbent filaments, 

 obovate. 

 Eivularia Leclancherii, CJiauv. — see. Lenorm. in litt. 



Hab. On decaying fronds of Rhodymenia palmata, probably common. 



Annual. Autumn. Torquay, Mrs. Griffiths. Down coast, Mr. W. 



Thompson, 1835. 



Geogr. Distr. Shores of Europe. 



Descr. Patches from a line to a quarter of an inch or rather more in diameter, 

 orbicular, or slightly irregular in form, composed at first of decumbent 

 filaments radiating from a centre, and spreading on the surface of the 

 Rhodymenia, closely cohering together into a thin membranous expansion, 

 which is finely serrated at the edges. As the plant advances to perfection, 

 vertical filaments, closely set together, spring in the centre of the patch, 

 where they form an umbo, and gradually are developed outwards, becoming 

 shorter and shorter as they approach the edge. Beyond this umbo a wide 

 margin, destitute of vertical filaments or with a few scattered short ones, 

 extends. Spores obovate, on long pedicels, or on the apices of abbreviated 

 filaments. At other times — and, indeed, more frequently — some of the 

 vertical filaments are found altered into lanceolate pod-like bodies, repre- 

 sented at fig. 4, jointed, but seemingly destitute of sporaceous matter. 

 Colour olive brown. 



In Autumn the fronds of the common Dulse (Rhodymenia pal- 

 matd) in passing to decay are commonly found covered with 

 roundish olive spots, which, by a hasty observer may be over- 

 looked as being nothing more than incipient mortification. By 

 placing a small portion of such a spotted frond under the micro- 

 scope, the beautiful parasite here figured is brought to light. It 

 was first pointed out to me by Mrs. Griffiths in 1845, who found 

 it very plentifully at Meadfoot, near Torquay, and who received 

 specimens identical in every respect from M. Lenormand under 



