CHLOROSPERME.E. 185 



Parasitical on the smaller Alga, generally on Ceramium rubrum. Fila- 

 ments 2 or 3 lines high, forming elegant, pencilled tufts, much branched ; 

 branches straight or somewhat flexuous, erect or slightly spreading, close 

 or distant, the upper ones often closely set with minute, bud-like, 1- or 2- 

 jointed ramuli. Capsules minute, elliptical, solitary or clustered. I fear 

 the distinctions pointed out in Br. Fl. between C. Daviesii and viryatu- 

 lum cannot be depended on ; the latter appears to be merely a more ad- 

 vanced state of the former : nor can I discover any permanent characters 

 by which C. lanuginosum and C. secundatum, Ag. may be distinguished. 

 Cat. Daviesii bears a very close resemblance to Trentipohlia pulchella, a 

 fresh-water Alga, inhabiting mountain streams. 



SUB-CLASS III. 

 CHLOROSPERME^E OR CONFERVALES. 



Harv. in Mack. Fl. Hib. part'\\\. p. 220, (1836) ; ZOOSPER- 

 , J. Ag. Alg. Medit. p. i. (1842). NOSTOCHINE.E, ULVACE^E, 

 CONFERVOIDE.E (in part.} Ag. Syst. pp. xv. xxxii. ZOOSPER- 

 ME.E and SYNSPORE.E, Dne. Sc. Nat. xvii. p. 305. CONFER- 

 VACE^: and part of PHYCE^E, Endl. PI. 3d Suppl. p. 10, 19. 

 CONFERVACE.E and part ofFuc^CEM, Lindl. Veg.Kingd. pp. 

 14, 20. (DiATOME^E, or DIATOMACE^E, of author s, are also a 

 part of this sub-class). 



DIAGNOSIS. Plants green, rarely a livid purple. Fructi- 

 fication : dispersed through all parts of the frond, the whole 

 colouring matter being capable of conversion into propagula ; 

 1, spores (Sporidia, Ag.), green or purple, formed within 

 the cells, often at maturity vivacious, moving by means of 

 vibratile cilia ; 2, coniocystae (Ag.), or external vesicles, 

 containing a dense, dark-coloured, granular mass, and finally 

 separating from the frond. Marine, or (more generally) 

 found in fresh-water streams, ponds, and ditches, or in 

 damp situations. (The marine species of this sub-class are 

 alone described in the present work}. 



The plants of this sub-class are, in the vast majority of 

 cases, at once distinguished from all other Algae by the bright 



