CRYPTOGAMIA ALG^E. 239 



often tufted; articulations shorter than their diameter, even, 

 areolar ; joints opake. GREV. Fl. Edin. 310. Conferva elongata, 

 DILLW. Conf. p. 80. t. 33. Hutchinsia elongata, HOOK. Scot. 

 ii. 87. 



Hab, On rocks in pools left by the tide, not common. 



This is a large species, generally about 8 inches high, dif- 

 fused ; the main stalk and principal branches as thick as 

 fine whip-cord, or rather they resemble the antennae or 

 horns of the lobster, to which they have frequently been 

 compared. The extreme branches are in general termi- 

 nated with a tuft of short and lighter coloured ones, the 

 articulations of which are not areolar, but longitudinally 

 striate, and separated by pellucid joints, exhibiting in fact 

 the structure of a Polysiphonia ; and, like the species of 

 that genus, I have seen these extreme branchlets termi- 

 nated with pellucid fibres. 



2. C. rubrum, red, bushy, much branched in a dichotomous 

 manner ; extreme branches short and forcipate ; articulations as 

 long or longer than broad, areolar, contracted and diaphanous in 

 the middle HOOK. Scot. ii. 84. GREV. Fl. Edin. 310. Confer- 

 va rubra, DILLW. Conf. p. 78, t. 34. C. nodulosa, LIGHTF. Scot. 

 994. 



Hab. On rocks and other algae, very common. 



Smaller than the preceding, more delicate and more highly 

 coloured. 



3. C. diaphanum, fine red, soft, much branched, diffuse ; branch- 

 es dichotomous, the ultimate ones rather tufted, forcipate ; arti- 

 culations subpellucid and contracted at the centre with red swol- 

 len joints. HOOK. Scot. ii. 85. GREV. Fl. Edin. 310. Conferva 

 diaphana, LIGHTF. Scot. 996. DILLW. Conf. p. 78, t. 38. Eng. 

 Bot. t. 1742. 



Hab. Parasitical on various algae, common. 



This frequently equals C. rubrum in size, from which it is 

 readily distinguished by its lighter colour, greater flac- 

 cidity, and more particularly, as Dr GREVILLE remarks, 

 by its diffuse mode of growth. Young plants are of a 

 uniform reddish-pink colour; they assume in their pro- 

 gress a duller red, and ultimately become spotted and yel- 

 lowish, presenting to the naked eye the appearance of a 



