20 M. FOSLIE. [1900 



vering up extraneous objects. Besides, in most of the specimens 

 seen a great number of Bryozoa and other animals contribute to 

 the irregularity in the development of the plant, and in part also 

 appear to contribute to divergences in structure. In this respect 

 it rather reminds one of Litliotliamnion funafutiense, the league 

 between plant and animal alm ost amounting to symbiosis. 



With reference to structure the species is more irregular than 

 any other one known to me. In a couple of sections examined 

 I have not seen any real hypothallic layer, but it may be remar- 

 ked that the crusts often almost alternate with Bryozoa or other 

 animals, and the lower parts of a crust sometimes at least are 

 almost mouldered. The basal cells seern to be elongated and ver- 

 tically oblique. Otherwise the layers of tissue are very irregular. 

 The cells are frequently rounded, seldom a little vertically elonga- 

 ted, partly small, 5 — 10 /x in diameter, partly and more frequently 

 larger, 10 — 18 /j-, or sometimes 25, occasionally up to 30 /i in 

 diameter. Here and there on a section are to be seen short or 

 longer, horizontal or feebly curved but indistinct rows of minute 

 cells at intervals of 3—6 layers of large cells. In the cortical 

 layer are some scattered and large ones which appear to be he- 

 terocysts. 



The conceptacles are subhemispheric or subhemispheric-conical, 

 300—400 fj- in diameter seen from above, and perhaps being those 

 of sporangia with the upper part fallen away, if not in fact stun- 

 ted organs of one or other kind without developed spores. I have 

 examined a rather great number of these conceptacles, but I have 

 not succeeded in tinding any trace of spores, partly being empty 

 partly filled with carbonate of lime in compact masses, or animals, 

 or sometimes even hard and reddish masses apparently of some 

 animal origin. On a section the conceptaeles most nearly agree 

 with those in Goniolithon. 



However, I am not sure whether the species in fact is a Go- 

 niolithon or perhaps Lithophyllum (Lepidomorphum). Here I refer 

 it to the former because it in several respects stands nearest to 

 G. Notarisii, although rather differing in habit, in which respect 



