Confervoideie, Cladophoracese, Microdictyon. 36l 



riter dichotomo, segmentis elongatis, distantibus, ad axillas parum 

 dilatatis, liic illic invicem conglutinatis, apice valde attenuatis; fi- 

 lamentis frondem constituentibus tenuioribus, conspicue articulatis. 

 Hab. ad aSorong)) Nova Guinea (0. Beccari). — Facies omni- 

 no Codii lomento^i. 

 3. Spongocladla neocaledonica Grun. in Murray et Boodle On tlie 959 

 structure of Spongocladia p. 175. — Thallo compacto, vix ranioso, 

 extus coloris griseo-flavescentis, intus viridis, 5-8 cm. alto; fila- 

 mentis frondem constituentibus crassis, haud in ramos distinctos 

 implicatis. 



Hah. ad a Poro » Novae Caledonise (Grunow). — Prope littus, 

 aqua non semper obtecta, crescit. 



Subfamilia tertia Microdictyeae. 



Thallus halophikis, articulis maxima ex parte iusimul irregulariter annsto- 

 mosantibus eflformatus et tunc retiforrai-pertusus. 



Microdiclyon. Thalius basi radicans, demum horizontaliter expansus et non- 



numquam ramulis radicantibus substrato adfixus. Rami omnes secus sin- 



gulam pKanitiem anastomosantes. 

 Boodlea. Thallus coactus, spongiosus; rami quoquoversum vergentes, inter 



sese secus plures plauities per tenacula adliterentes. 

 .^5/rwyca ') Thallus stipite monosiphonio donatus, superne ramosus, ramis 



nonnullis vel omnibus insimul retiformi-anastomosantibus. 



MICRODICTYON Decaisne [1839] Pl. de IWrab. in Arch. du Museum II 

 (Etym. micros parvus et diciijon retis) Kuetz. Species Algarum 

 p. 511, Gray in Journ. of Botany 1S6G, p. 45, Ilauck Meeresal- 

 gen p. 467, Ardiss. Phyc. Medit. II, p. 182. — Thalius reticula- 

 tus, membranaceus, e filamentis ai'ticulato-ramosis, in eodem plano 

 reticulatira anastomosantibus constitutus venisque utriculosis irre- 

 gulariter percursus. 

 Multiplicatio .? 



1. Microdictyon umbilicatum (Veiley) Zanard. Icon. Phyc, Adriat. 96u 

 I, p. 79, t. XIX (excl. synon. M. Calodictyon), Hauck Meeresalgen 

 p. 467, t. 203, Ardiss. Phyc. Medit. II, pag. 183, Microdicixjon 

 Agardhianum Decaisne Pl. Arab. p. 115, Hydrodiciyon umbili- 

 catum Ag. Syst. pag. 85, Conferva umbilicaia Velley in Linn. 



1) Vix Siphonocladiacea, observante cl. J. Aganlh Tiil Algernes Syste- 

 matik Vill, p. 109. 



