CALOTR1CHE.E. 277 



plant, and the upper portion towards the base, and each parallel and 

 coherent with the other, and not usually separating until another dislo- 

 cation has taken place in the endochrome of one of them, so that the 

 filaments cohere mostly in pairs throughout the plant, though some- 

 times four or more filaments are coherent within one common sheath. 

 The apparent branch (which is really a portion of the original filament) 

 always extends beyond the filament from which it appears to be 

 given off." 



The dried specimens, which alone we have seen, are insufficient to 

 determine the true relationship of this plant, hence, as well as the next, 

 their position must be accepted as provisional. 



Plate CXIIL Jig. 2. a, natural size ; b, portion enlarged j c, d, e, 

 trichomes X 400 diatn. ; c and d, after Berkeley. 



Species uncertain. 

 Calothrix (?) Smithii. (Berk, in Eny. Bot.) 



Filaments red, creeping, branched, contained, with their 

 ramifications, within a tough, more or less permanent sheath, 

 which bursts irregularly, endochrome annulated, very slender, 

 green, joints about as broad as long. 



SIZE. Not stated. 



Ccenocoleus Smithii, Berk. Eng. Bot. t. 2940. 



On moors. 



" Forming a red rugose mat of interlacing threads on boggy soil, 

 where it is very conspicuous, but from which it is separated with diffi- 

 culty on account of the roots and fibres of heath and moss to which it 

 adheres. 



" Threads elongated, branched laterally and acutely, their outer coat 

 being cartilaginous, within which fresh branches are generated and creep 

 within it till it is ruptured, when their free apices repeat the same 

 phenomena. Occasionally some of the rainuli burst through the sheath 

 at the base in pairs, as in genuine Scytonemata. Endochrome very 

 slender, green, the articulations about as broad as long." M. J. B. 



GENUS 114. RIVULARIA. Roth. (1824.) 



Frond having a tendency to an hemispherical or bladdery 

 form. Filaments agglutinated by a more or less firm mucilage, 

 exhibiting a disposition to radiate from the base of the frond. 

 Frond usually with a well-defined outline. Heterocysts basal 

 (placed at the base of the principal filaments and branchlets) . 

 Ramifications produced by the transverse division of the 

 trichomes, the upper part of which detaches itself and becomes 

 a lateral branch! et, while the lower part, extending itself by the 

 side of the old tip, makes a new extremity similar to the first. 

 Trichomes never producing any spores. 



