No. 2] NEW SPECIES OR FORMS OF MELOBESIEAE. 7 



thall us except a narrow peripherical portion. They are frequently 

 subprominent, flattened subhemispheric, 0.7 — 1 mm. in diameter 

 seen from above, and the roof is intersected with about 80 muci- 

 ferous canals. The sporangia are four-parted and very large, 

 250 — 350 fi long and and 100—150 fi broad. The conceptacles 

 of cystocarps also are crowded, often so densely that they become 

 angular, subhemispheric-conical, 0.6 — 0.9 mm. in diameter seen from 

 above. In thick and lumpy specimens the}' are exceptionally even 

 developed in the lower part of the frond. 



The roof of the conceptacles of sporangia appears frequently 

 to get dissolved at maturity and the scars filled by new formed 

 tissue especially in thin crusts. Sometimes however the concep- 

 tacles become in part overgrown even before the sporangia are 

 mature, and at length fully overgrown, but the sporangia are then 

 as a rule escaped. The conceptacles of cystocarps seem to be 

 overgrown in the same proportion as the former, sometimes also 

 these in part before the spores are mature, become however fre- 

 quently emptied before fully overgrown. Such emptied and nearly 

 overgrown conceptacles sometimes look, as if they had not or 

 scarcely been raised above the surface of the frond, as the oriflces 

 now and then do not become covered before several layers of 

 tissue are formed over the conceptacles, and therefore on a section 

 appearing rather elongated. This however occasionally takes place 

 also in other species. 



The plant stands between L. Patena and L. lichenoides, in 

 .some respects forming an almost intermediate link between both, 

 sometimes much resembling the former in habit, sometimes however 

 rather differing. 



Occurrence. Pacific coast of North America: Monterey, Cali- 

 fornia, W. A. Setchell; and Port Renfrew (Port San Juan), 

 Vancouver Island, B. C. on Cheilosporum frondescens between tide 

 marks, collected by Mr. K. Yen do of Tokyo. 



Goniolithon mamillare (Harv.) Fosl. 



Melobesia mamillaris Harv. Ner. Austr. p. 111. 



f. litoralis Fosl. mscr. 



