356 Algae. 



fiora. The freshwater filamentous Algae of the Tropics are prevalently 

 narrow forms, a fact vvhich is brought in relation with the small 

 amount of dissolved oxygen in the water. Exceptions are constituted 

 by Pithophora and Spirogyra, especially by the latter. Cladophora 

 and Rhisoclonium are verj^ poorly represented in tropical freshwaters 

 and there is good evidence to show that in most cases they favour 

 well-aerated (e. g. running) water. The chief representative of Clado- 

 phoraceae in the Tropics is Pitophora, which appears to be an 

 essentially tropical genus. Vaiicheria is very rare in the Tropics; 

 this refers especially to the aquatic species, but the terrestrial ones 

 are not much commoner. Botrydiuni is equally rare. The Confervales 

 are not very well represented, the most abundant form being 

 Ophiocytmm ; Conferva tends to be restricted to well-aerated water. 

 It is possible that Vmicheria and the Confervales are not well suited 

 to the Tropics owing to their peculiar assimilatory process. In the 

 case of the Ulotrichales it is not quite evident at present whether 

 they attain an adequate development in tropical freshwaters. The 

 genus Spirogyra is even more abundant in the Tropics than it is 

 with US. The species so far recorded are mainly broad forms with 

 two or many chloroplasts in their cells; forms with infolded end- 

 walls are strikingly rare. The other genera of Zygnentaceae are not 

 very abundant. There is a marked filamentous tendency among the 

 Desmids of tropical water (especialy in certain kinds of stagnant 

 water), and this may again be due to the poor aeration of the 

 water. The genus Oedogonium is very abundant but is mainly 

 represented by species with narrow filaments. Freshwater Florideae 

 appear to be not at all uncommon in the Tropics. F. E. Fritsch. 



Löfgren, A., Contribui^oes para a algologia paulista, Familia 

 Oedogoniaceae. (Secretaria de Agricultura, Commercio e Obras 

 publicas do Estado de S. Paulo. Boletim do Horto botanico. 8*'. 

 31 pp. et 6 planches. S. Paulo. 1906.) 



Le directeur du Jardin botanique de S. Paulo donne dans cette 

 brochure la premiere contribution ä la flore algologique de l'Etat 

 bresilien de S. Paulo et, autant que je sache, la premiere publication 

 importante faite au Bresil sur ce groupe de plantes. L'auteur, qui 

 s'est occupe depuis de longues annees des algues d'eau douce de sa 

 region, en fait ressortir, dans sa preface, la richesse au point de vue 

 algologique. Apres avoir expose d'une maniere tres succincte la 

 morphologie de la famille des Oedogoniacees , l'auteur donne une clef 

 analytique des especes rencontrees jusqu'ici ä S. Paulo, suivie d'une 

 description detaillee des especes (en portugais), avec indication 

 de leur aire geographique. La richesse de la region exploree en 

 Oedogoniacees ressort du fait, que sur les 33 especes citees (30 Oedo- 

 gonium et 3 Bulbochaete) il n'y a pas moins de 12 especes et 4 

 Varietes et formes nouvelles, savoir: Oedogo}niim argyrosporum'^ordsi. 

 et Hirn., O. tapJirosporum N. et H., 0. stibrectnni Hirn, O. simp/exH., 

 0. crispuni Wittr. vstr. proprium H., 0. Pringskeiniii {Cram.),Witir. f. 

 abbreviatum H. , O. porrectum N. et H. , O. hians N. et H., O. rigi- 

 dnni H., O. tentoriale N. et H. , O. decipiens Wittr. f. dissimile H., 

 O. paulense N. et H., O. urceolatiim N. et H., 0. spurium H., 

 O. pulchrum N. et H., Bulbochaete elatior Pringsh. f. pumila H. 

 Toutes les espfeces sont figurees sur les 6 planches qui accompagnent 

 le texte. J. Huber (Parä). 



