LYNGBY^E. 255 



" Trichomes enclosed in a transparent sheath from which they emerge to 

 reproduce new filaments, sheath containing several trichomes. Fila- 

 ments growing in scattered creeping erect or floating wick-like bundles." 

 Thtiret. 



Hydrocoleum tliermale Kutz., mentioned in Quart. Journ. Micr. Sci. 

 (1867) p. 86, as having occurred in Ireland, we have never seen, and, 

 therefore, do not know whether it should be included in Microcoleus. 



Microcoleus gracilis. Hass. Alg. 261, t. 70, /. 2. 



Effused broadly in a thin dark green stratum. Trichomes 

 pale blue green, slightly curved, in fascicles densely contorted 

 about the apex, joints 2-3 times longer than their diameter, 

 either continuous or distinctly separated, granulated, divisions 

 paler, nearly hyaline, a little contracted about the apex, extreme 

 apiculus conical, now and then slightly carved, special sheath 

 narrow, very delicate, universal sheath very thick lamellose. 



SIZE. Trichomes 0025--003 mm. ; fascicles 09-*12 mm. 



Kirch. Alg. Schl. 244. 



Microcoleus marinus, Harv. Man. 168. 



Chthonoblastus salinus, Kutz. Tab. Phyc. i., t. 58, f. 2. Rabh. 

 Alg. Eur. i., 133. 



Oscillatoria chthonoplastes, var. a. Eng. Fl. v., 373. Eng. 

 Bot. ii., t. 2523. Mack. Hib. 239. 



On salt marshes. 



"Fronds fixed at the base, floating freely in the water, an inch long, 

 tufted, dichotomously branched, branches slender capillary widening up- 

 wards, with club-shaped tips ; colour olivaceous green or yellowish. 

 When ruptured the branches discharge innumerable needle-shaped fila- 

 ments, which, when the plant is growing, radiate and oscillate from the 

 tips of the branches." JJarvey. 



Plate XCIX. fig. 1. End of fascicle of trichomes with sheath X 400. 



Microcoleus chthonoplastes. Thur. in Ann. Sci. Nat. (1875) 



p. 377. 



Stratum thin, or thicker and rather compact, dingy seru- 

 ginous green ; trichomes slightly flexuous, equal, twisted, in 

 dense fascicles, joints nearly twice as long as their diameter, 

 rather remote from each other, leaving a hyaline space between 

 them, apiculus attenuated, rather elongated ; special sheath 

 very delicate, universal sheath narrow, scarcely lamellose. 



SIZE. Trie-homes > 0035-'004 mm. ; fascicles -03--035 mm. 



Chthonoblastus Lyngbyei, Kutz. Tab. Phyc. i., t. 58, f. 1. 



Microcoleus anguiformis, Hass. Alg. 261, t. 70, f. 1. Kirch. 

 Alg. Schl. 244. 



Chthonoblastus anguiformis, Kutz. Tab. Phyc. i., t. 57. Rabh. 

 Alg. Eur. ii., 133. Harv. Phyc. Britt. t. 249. 



On the naked ground, by roadsides, &c. 

 Plate C.fiy. 1. Fascicle of trichomes with sheath X 400. 



