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In classifying this species 1. c. it seemed strange to me that the conceptacles of sporangia, 

 in a section made thin by grinding, wen- rather differing in shape from those in typically 

 developed specimens of Lepidomorphzim, one of the two subgenera of Lithophyllum. However, 

 I classed it wit h the latter, as at the time I had not the opportunity for examining it more 

 carefullv. nor did I possess good sections. Besides, the conceptacles were smaller than usual in 

 iolithon, and externally rather resembling those of the genus mentioned above. Afterwards 

 l have had the opportunity of examining a larger material of the plant, and now l consider 

 it to be a Goniolithon, although only sporangia are known. The most certain distinguishing 

 feature between the said two genera is owing to the cystocarps. But also the sporangia are 

 differing, in as much as in Goniolithon they arise from any part of the disc almost plain or 

 sometimes even faintly cup-shaped, whereas in Lithophyllum they arise around the peripherical 

 parts of the disc more or less overarched. Sometimes, however, the snbgenus Lepidomorphum 

 and the genus Goniolithon are not clearly distinguished only on account of the sporangia, as 

 these organs, particularly in the said subgenus, often detach themselves, before or towards 

 maturity, from the bottom of the conceptacle and are then to be found around the walls of the 

 latter. This is especially the case when the conceptacle is small in proportion to the number 

 of sporangia developed. In Lithophyllum they often, or rather as a rule, lean against the walls 

 of the conceptacle even before detached from the disc, as now and then seems to be the case 

 also in Goniolithon. In addition, heterocysts occur in the genus in question, but in sporangia- 

 bearing specimens of certain species they seem to be very scarce. In Lithophyllum, on the 

 other hand, heterocysts do not appear, as far as I have hitherto seen. 



In a young stage the plant forms thin crusts on corals or other hard objects (PI. X, 

 fig. i). It soon develops excrescences or short branches, the latter, however, only once divided 

 in some of the specimens which I have examined. They are densely crovvded and by and by 

 anastomosing, so that only the uppermost part is free (PI. X, fig. 2 — 5). In this part they are 

 frequently 4 — 5 mm. in diameter, sometimes, however, thinner and less confiuent (PI. X, fig. 6). 

 The shape ot the plant depends on that of the substratum, in general, however, showing a 

 tendency at length to form roundish balls, which attain a diameter of up to about 8 cm. It 

 often shares substratum with other species, particularly Archaeolithothamnion erythraeum and 

 Lithophyllum Okamurai, and it now and then grows over, but, on the other hand, it some- 

 times also becomes overgrown by such ones. Cp. pi. Y, hg. 11, where this species is almost 

 covered with A. erythraeum. PI. XI, fig. 16 represents a specimen the greater part of which 

 belongs to L. Okamurai, being however confiuent with the species in question, which is visible 

 lowest to the left on the picture, or even to the right between the branches of the former. 

 Some of the branches of G. Reinboldi are marked with a cross on the picture. PI. IX, fig. 13 

 also represents a specimen with a few branches ot the species in question, here sharing sub- 

 stratum partly with /.. Okamurai, partly and especially Goniolithon laccadivicum. 



\ vertical section of the crust shows that the hypothallium is composed of a solitary 

 layer of cells. The latter are vertically elongateel, frequently more or less oblique and 15 — 25 •].. 

 long. The perithallium is thoroughly formeel by very irregular cells. They are partly rounded, 

 partly angular, in general 12 — 25 u. in diameter, occasionally, however, somewhat vertically 



