276 NEMATOGENJE. 



Calothrix. Orsiniana. Thur. Ann. Sci. Nat. 



Forming a pulvinate stratum, as much as two lines in thick- 

 ness, dark brown, lubricous, opaque ; trichomes elongated, 

 branched, of nearly equal thickness, cuspidate at the apex or 

 obtuse, distinctly articulate, here and there moniliform ; sheaths 

 thick, lamellose, golden brown, from the base to above the 

 middle even, apical portion more or less dividing in fibrous 

 lamellae. ' 



SIZE. Trichomes with sheath -01-'012 mm., without sheath 

 004--006 mm. 



Kirch. Alg. Schles., p. 219. 



Scytonoma cirrhosum, Berk. Eng. Bot. ii., t. 2920. 



Ccenocoleus cirrhosus, Berk. Eng. Bot. ii., sub. t. 2940. 



Schizosiplwn cataractce. Nag. in Kutz. Tab. Phyc. ii., t. 52, 

 f. 1. Rab. Alg. Eur. ii., 235. 



On rocks and submerged stones. 



Although we have seen no authentic specimen of Berkeley's C(enoco- 

 Ivus, the specimens from Ben Lawers, which we have referred as above, 

 appear to us to belong to the same species, as far as can be judged in the 

 absence of all measurement. 



Plate CXI1I. fig. 1. Portion of trichorne X 400; J, small fragment 

 magnified with sheath from Eng. Bot. t. 2920 ; c, cells of trichome free 

 from the sheath. 



Calothrix Dillwyni. (Hass. Alg.} 



Flaccid, bluish green or brown, trichomes usually cohering in 

 pairs, sheaths inconspicuous, except towards the base, joints 

 about half as long as their diameter, heterocysts at the base of 

 the branches ovate or cordate. 



SIZE. Trichomes -005--006 mm., with sheaths -OOS-'Ol mm. 



De&monema Dillwynii, Berk. Eng. Bot. ii., Supp., "t. 2958. 



ToUjpothrix Dilhvyni, Hass. Alg. 242, t. 68, f. 4-5. 



Microcolens Dillwyni, Harv. Man. 169. 



Conferva vaginata, Dillw. Conf., t. 99. 



On mosses and moist rocks. 



Plant minute, flaccid, much branched, seldom a quarter of an inch in 

 length, varying in colour from brown to bluish green. Filaments 

 usually cohering in pairs. Sheaths inconspicuous, except those of the 

 older filaments at the base of the plant, which become thickened and of 

 a reddish brown colour. Endochrome annnlated, more evidently so in 

 the recently formed filaments than at the base of the plant, dotted from 

 the presence of minute granules; joints about twice as broad as long, 

 the terminal one somewhat dilated and hemispherical. The branches 

 towards the base of the plant are seated each upon a connecting cell 

 (heteracyst) of an ovate or cordate form. The plant possesses other 

 branches formed by a dislocation of the endochrome, each separated 

 portion becoming elongated, the lower portion towards the apex of the 



