On the Pithophorace^. 3 



specimens perfectly verified my conjecture, expressed above, that this 

 species belonged to the genus Pitliophora. The Grunowian collection 

 also contained an original specimen of the Cladophora sumatrana v. 

 Mart, mentioned above. Moreover, another form belonging to this 

 genus was found in the collection; it was from Mangalore in India and 

 was identified by Kiitzing as Clado])liora crispata ^) (the identification 

 corrected by Grunow to Cladophora Roettleri), — and also another, be- 

 longing to this group, from La Guayra in Venezuela, called Cladophora 

 Roettleri var. Besides these, which existed in fertile specimens, the 

 Grunowian collection contained specimens of sterile ^) Pitliophoraceœ^ 

 partly from South America and partly from Australia. 



Judging from the species as yet known, the family contains only 

 tropical and subtropical forms (the one found in »Tropical Aquarium» 

 in Kew probably also has its origin from the tropics), all growing either 

 in fresh water ^) or, as is the case with the one found by Professor 

 Cleve in the West-Indies, and probably also with the one collected by 

 V. Martens in Japan, on moist earth. 



Before passing to an accoimt of the natural history of the Pitho- 

 pjhoracece^ I will here embrace the opportunity of offering my hearty 

 thanks to Mssrs Professor E. von Martens, Professor P. T. Cleve and 

 D:r A. Grunow for the valuable assistance they have rendered me by 

 putting at my disposal precious material from their respective collections. 



In the following exi)osition of the morphology and systematic 

 arrangement of the Pithophoraceœ, I begin by describing the construction 

 of their vegetative system,, and then treat, in different paragrajîhs, the 

 formation of their reproductive organs, thei'r germination and increase, 

 their whole development succintly, their place in the natural system, 

 their specific characters, their geographical distribution, and finally I give 

 a special account of the forms, as yet known, belonging to this group. 



') Tliis form is commiinicated under the same name in Hohenaceee's Algaî 

 marinas siccatœ, n:o 742. 



-) Even as sterile the Fithoplioraccce may generally be distinguished from 

 Cladoplwreœ. Kegarding this, see below, pag. 4. 



3) The australian form, found in the collection D:r Geu>"OW has kindly put at 

 my disposal, is said to occur in slightly brackish water also, 



