No. 3] REMARKS ON NORTHERN LITHOTHAMNIA. 105 



to decay. In dried specimens of Melobesia coronata, however, is 

 partly found a distinct corona, in all essentials consistent with the 

 picture given by Mr. Rosanoff 1. c. pi. IV, fig. 9. 1 ) Among the 

 said conceptacles in M. Lejolisii it is tnose of sporangia whose 

 cells around the orifice are 10 — 12 p. long, while those of cysto- 

 carps mostly seem to be shorter. Perhaps it is the conceptacles 

 last mentioned which are in a certain phase of development car- 

 rying the corona described by Mr. Rosanoff. In the M. fari- 

 nosa the state of things is nearly the same as that of M. Lejolisii 

 described above, the corresponding cells of some conceptacles, 

 however, being 15 — 18 fi long. 



As I already observed under M. farinosa, these two species 

 are easily confounded one with the other, when they are not well 

 developed. The same is the case habitually with young or feebly 

 developed specimens of Lithophyllum (Dermatolithon) pustulatum 

 (or L. macrocarpum) and M. Lejolisii, which are often growing 

 gregariously on the same substratum. As is besides evident from 

 the synonyms, and as I have already observed under Lithoth. 

 membranaceum, M. Lejolisii has partly been referred to this spe- 

 cies. This even appears to have been done by Mr. Rosanoff 

 himself. Cp. above under the said species. Mr. Rosanoff de- 

 clares 1. c. that M. Lejolisii occurs at Cherbourg on Zostera and 

 on Bornetia, but is not known on other algae. The form distri- 

 buted by M. Le Jolis under no. 240 by the name of M. pustu- 

 lata, however, essentially represents M. Lejolisii and small crusts 

 of L. membranaceum. I have examined two specimens of the 

 no. mentioned, and one of them also includes a minute crust which 

 has not been closely examined, but which is likely to belong to 

 L. pustulatum (or L. macrocarpum). The species in question and 

 Lithoth. membranaceum, however, are, as a general rule, easily 

 recognizable, if they are not growing together on the same sub- 

 stratum and L. membranaceum only carrying conceptacles of cysto- 



1 ) In Siboga Exp. LXI, p. 57 I have written that the conceptacles of c}rsto- 

 carps have no corona. This is a misstatement owing to a lapsus calami. 

 All the conceptacles examined in a dried specimen had a ciliated orifice, 

 but in some of them the cells mentioned are rather short. 



