Ser. MelanosfermejE. Fam. Bictyotea. 



Plate CCXCV. 



LITOSIPHON LAMINARLE, Haw. 



Gen. Char. Frond unbranched, cylindrical, filiform, cartilaginous, sub- 

 solid, at length tubular, composed of several rows of cells ; the 

 surface areolated. Fructification solitary or aggregated, naked spores, 

 scattered irregularly over the surface of the frond. Litosiphon 

 {Harv.), — from \itos, slender, and cncpau, a tube. 



Litosiphon Laminarice ; fronds stellately tufted, short, cylindrical, blunt, 

 slightly tapering at the base, smooth (or hairy toward the apex), 

 transversely banded, the bands close together; spores scattered, or 

 several in each transverse band. 



Litosiphon Laminariee, Hart). Man. ed. 2. p. 43. 



Desmotrichum Laminarise, Kiitz. Sp. Alg. p. 470. 



Chlorosiphon Laminarise, Harv. inFkyc.Frit. vol. i. p. x. {list of species.) 



Bangia Laminaria?, Lyngb. Eyd. Dan. p. 84. t. 24. Ag. Syst. p. 75. Hook. 

 Br. Fl. vol. ii. p. 316. Harv. in Mack. Fl. Hib. part 3. p. 241. Harv. Man. 

 ed. 1. p. 172. 



Asperococcus ? Laminariae, /. Ag. Sp. Alg. vol. i. p. 79. 



Hab. Parasitical on the fronds of Alaria esculenta, common on that plant 



in the summer and autumn. Annual. 

 Geogr. Distr. Atlantic shores of Europe. 



Descr. Fronds from a quarter to half an inch in length, cylindrical, slightly 

 tapering at the base, then of nearly equal diameter upwards, and ending in 

 a blunt point, smooth, or beset toward the summit with slender pellucid 

 fibres, at first solid, becoming hollow in age from the perishing of the 

 central cells. Structure built up of two or three or more layers of con- 

 centric cells ; those of the outer circle, or periphery, about as long as broad, 

 placed tier above tier in regular circles, so that the frond appears as if trans- 

 versely striate or banded. The cells sometimes separate into four smaller 

 cells, which occupy the space of one large cell. Spores ? scattered, one or 

 more in each transverse band, each spore formed from a cell of the band, 

 become enlarged and prominent. Colour, when young, a clear olive, be- 

 coming brown in age. Substance soft, adhering to paper. 



This poor little plant has been sadly tossed about among bota- 

 nists from one part of the system to the other, nor is it yet very 

 certain whether it will be allowed to bear the Dame under which 

 it is now described, or whether that must be changed into 

 Desmotrichum. Should it be found, on comparison, to agree in 



