edition, its habitat being awaj to the west. rhe occurrence of this species in Eastern 



f much interest rhe head-quarters of the genus maj 1"- regarded as being in the 



I (ndies, fi-om which the other two species are recorded. rhe genus has not been found 



A similar distril rs in Rhipilia y two species of which are found in the western 



t r« »i >i the Indian < >cean. Penicillus is similar in being mainly Wesl 



Indian ; and it h.is tv. ientatives in Eastern waters and one in tin- Mediterranean. 



7. Rhipidodesmis gen. nov. 

 (Figs. i.p 11; 



ants filamentous, gregarious, laxl) caespitose, uncalcified; below decumbent, colourless 

 and irregularly ramified, very laxly entangled (never densely felted so as to form a spurious 

 ascending above, viridescent, fastigiately or flabellately ramified towards the apcx, 

 \ constricted above the dichotomies ; upper dichotomies approximated. 



1. Rhipidodesmis caespitosa comb. nov. 



Syn. Chlorodesmis caespitosa J. G. Agardh Ti 11 Alg. Syst. Y. iS.x-. p. 49. 



Avrainvillea caespitosa Murray & Boodle in Journal of Botany XXVII. [889. p. j:, pro parte. 



Avrainvillea caespitosa De Toni Syll. Alg. I. [889. p. 516. 



/lab. INDIC. Ceylon, Colombo, Ferguson n" 110! 



Plants aböut 3 cm. long, gregarious in wide, lax, green patches ; filaments cylindric, 

 decumbent and colourless below, occasionally producing lateral branches, often constricted and 

 furnished with annular or excentric stoppers, and containing much starch ; ascending and 

 viridescent above; dichotomial divisions distant below, much more approximate towards apex; 



il pseudo-articuli often short, oblong; trichotomy not infrequent; filaments always evenly 

 constricted at the dichotomy or trichotomy, measuring 120 — 1 50 a diam., usually collapsed, 



it 200 ■]. when Hat. [Figs. 141 — 143]. 



1 laving nothing hut the dried material of this plant to examine, we are unable t<> 

 state whether the successive dichotomies of the filaments are normallv at right angles with one 

 another, or whether they occur in one and the same plane and are forced out of position by 

 the crowding of the ramelli. Certainly the apical branchlets do overlap one another to some 



fig- ' 1 



The apical branching of this species distinguishes it generically from Chlorodesmis comosa, 



and •. its position in a new genus intermediate between Callipsygma and Chlorodesmis. 



It r< i the latter genus in its long filamentous habit, and approaches Ca/lipsv^ii/a (Tijg. 



ly indeed in its green complanato-fastigiate apical ramification lig. 1 pv, which 



elj coloured denser contents. It differs from Chlorodesmis comosa in the apical 



and in not possessing the moniliform and longly radicelliferous basal filaments. 



i in having much thicker upper filaments (compare hg. 142 with lïg. 69). 



ir peripheral ramifications of Rhipidodesmis and Callipsygma suggest in a 



