57 



around the orifice, forming a corona. These conceptacles are 250 — 350 u.. in diameter, when 

 seen from above, but they are often not distinctly defined. The sporangia are four-parted, 

 about 75 — 85 u. long and 35 — 40 u. broad. In other crusts of the same specimen are to be 

 found conceptacles, which are lower or less conical than the above mentioned ones, and the 

 cells of the orifice are not or but a little elongated. They are of about the same diameter as 

 the conceptacles of sporangia, or sometimes a little larger. These are cystocarpic conceptacles, 

 which seem as a rule not to occur in the same crust as those of sporangia ; but when several 

 crusts are found on the same substratum, both organs may be met with in the neighbour- 

 hood of one another. In the same specimen appear also a few other conceptacles, which are 

 of about the same shape as the cystocarpic ones, but they are only 100 — 150 u. in diameter, 

 when seen from the surface. These I suppose to be the conceptacles of antheridia. 



With some reservation I refer to the species in question the plant stated above from 

 Borneo bank, forming small, sterile and fragmentary crusts on Padina. The crusts are rather 

 brittle and have for the greater part fallen away, so that the original shape is no more to be 

 seen. The plant seems however to belong to M. coronata and to be most closely allied to 

 the form zo na fa. 



In Laurencia obtusa and Laurencia concinna from the places above quoted appear some 

 very small crusts in company with Melobesia farinosa. They are provided with cystocarpic 

 conceptacles of about the same size and shape as those in typical M. coronata, with in part 

 mature carpospores, and the structure coincides in the main with that of the latter. So also in 

 regard to a few crusts, about 1 mm. large, which together with iSIelobesia farinosa are attached 

 to eelgrass. They bear conceptacles which probably are young cystocarpic ones. 



The specimens here mentioned are partly too fragmentary, partly too feebly developed 

 to be determined with certainty, especially since the characteristic conceptacles of sporangia 

 are wanting. 



According to Rosanoff 1. c, Dcrmatolithon pustulatum (Melobesia pustulata auct.) 

 frequently accompanies Melobesia farinosa in the northern temperate zone. It seems, as if the 

 former is, in the area in question, replaced by Melobesia coronata, which here apparently now 

 and then accompanies the said species. 



Occurrence: The plant seems to occur very sparingly in the places above quoted, 

 and has hitherto not been met with in a well developed stage. 



Area: "Australia" (herb. Lenormand), the type of the species; Indic: South Australia 

 (f. zonata). 



Lithophyllum Phil. (Fosl. emend.). 



Subgen. Euli thophyllum Fosl. 



a. Crustacea. 



1. Lithophyllum oncodes Heydr. PI. XI, fig. 5 — 10. 



Lithothamnion oncodes Heydr. Neue Kalkalg. p. 6, t. I, fig. 1 1 ; ex parte. 

 Lithophyllum oncodes Heydr. in Ber. der Deutsch. Bot. Gesellsch. 1897, p. 410. 



SIBOGA-EXPEDITIE LXI. 8 



