On THE PITHOPHORACEA. — 38 
specimens perfectly verified my conjecture, expressed above, that this 
species belonged to the genus Pithophora. 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 Cladophora 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 *) Pithophoracea, 
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 
Cieve in the West-Indies, and probably also with the one collected by 
vy. Martens in Japan, on moist earth. 
Before passing to an account of the natural history of the Pitho- 
phoracee, 1 wil here embrace the opportunity of offering my hearty 
thanks to Mssrs Professor E. von Martens, Professor P. T. Cueve 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 exposition of the morphology and systematic 
arrangement of the Pithophoracew, | begin by describing the construction 
of their vegetative system, and then treat, in different paragraphs, the 
formation of their reproductive organs, their 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. 
1) This form is communicated under the same name in HonEnacxer’s Algw 
marine siccate, n:o0 742. 
*) Even as sterile the Pithophoracce may generally be distinguished from 
Cladophoree. Regarding this, see below, pag. 4. 
3) The australian form, found in the collection D:r Grunow has kindly put at 
my disposal, is said to occur in slightly brackish water also, . 
