28 M. FOSLIE. [1899 



eimens with simple branches or nearly so sometimes widely dis- 

 persed over the substratum, in older specimens not so densely 

 crowded, and not or but here and there regularly fastigiate. Howe- 

 ver, this is at least in part due to the very irregular objects to 

 which it sticks and sometimes surrounds, as old specimens show 

 transitions to f. fastigiata. It is probably but a form of the pre- 

 sent species, and the rather considerable difference in habit even 

 between young specimens of both forms not unlikely being due 

 to local, especially tidal conditions. In both forms grains of sand 

 become overgrown in smaller or greater number which appear to 

 contribute to the more or less anastomosing of the branches. 



The conceptacles of sporangia are developed in the upper 

 parts of the branches, solitary or somewhat crowded. They are 

 at first slightly convex, not sharpty defined and often difficult to 

 detect. On a transverse section they are only about 120 jj. in 

 diameter. The sporangia are four-parted, about 50 /^- long hy 

 20 jj.. The structure has not yet been examined. 



This species is known from Phillip Island, east off Port Phillip 

 Bay, and from Western Port, Victoria, Australia, in both places 

 growing on a depth of 2 — 5 fathoms, in company with another 

 species which not unlikely is identic with G. hrassica-florida 

 (Harv.) or &■(?) mamillosum (Hauckii), the latter two species 

 however not yet perfectly known. Here it has been found by 

 Mr. J. Gabriel. 



Lithophj^llum incrustans Phil. 



in Wiegm. Arch. 1837. 



f. depressa (Cm.) Fosl. 



Norv. Lith. p. 94. 



Lithothamnion depressum Crn. Fl. Finist. p. 151. 



f. Harveyi Fosl. 



Norv. Lith. p. 94. 



f. angulata Fosl. 



Some new or. er. Lith. p. 17. 



f. lolata Fosl. mscr. 



Melobesia polymorpha Harv. Ner. austr. p. 110? 



