241 



this species consists of three cell-layers, the middlemost of which is composed of 

 high cells, must refer to the fertile part of the crust (comp. fig. 159 D); but the 

 author says that she has observed three layers also at a great distance from the con- 

 ceptacles. Possibly, the specimens referred to this species by Mme Lemoine do 

 not all belong to it. In Calc. Alg. Med., 1915, p. 19, the same author mentions spe- 

 cimens of this species from the Mediterranean consisting only of two layers of cells, 

 the upper being the cortical cells; these specimens thus agree with the Danish ones. 



The conceptacles 

 of sporangia are usually 

 densely crowded. They 

 are low conical or, when 

 very densely placed, de- 

 pressed, with almost 

 level surface (figs. 156 

 — 158). The orifice is 

 rather narrow, almost 

 cylindrical, not enlar- 

 ged upwards, clothed 

 with unicellular hairs 

 of varying length. In 

 rare cases I found the 

 hairs long and protru- 

 ding outwards in a ver- 

 tical direction (fig. 158 D), 

 as drawn by Rosanoff 

 in fig. 11, pi. I, 1. c, but 

 usually they are shorter, 

 directed inwards hori- 

 zontally and not pro- 

 truding (figs. 156 E, 157 

 A, comp. Rosanoff's 

 fig. 8). The last quoted figure of Rosanoff certainly represents a normal, fully de- 

 veloped state. FosLiE, who did not find any protruding crown at all in examining 

 numerous specimens, thought that this might perhaps be owing to the fact that he 

 had only had dried material for examination, "or it may be that the cells of the 

 corona have a short phase of development and are soon falling to decay". My 

 investigations do not favour these suppositions; it must be supposed, that the de- 

 velopment of the hairs is variable according to the various conditions. — The roof 

 of the conceptacle is rather thin, consisting of about 2 (1 — 3) cell-layers, only a 

 little thicker, if at all, near the orifice. The floor of the conceptacle consists of a 

 single cell-layer; more rarely this cell-layer is absorbed (fig. 157 A). In some cases 

 a sterile columella was observed in the centre of the conceptacle (fig. 157 C), but 



D 



Fig. 158. 



Melobesia Lejolisii, Irom TG, north of La'so. A, frond seen from above, at left a 

 trichocyle. B, vertical section of antheritiial conceptacle, not yet ripe. C. vertical 

 section of antlierldial conceptacle provided with a spout. D, vertical section of 

 sporangia! conceptacle with well developed peristomial hairs. E, the same spor- 

 angium as seen in D. from a following section. B and C 650:1, the rest 350:1. 



D. li. 1). Viik'ilsk. Selsk Ski'., 7. H:ukkc, naturviileiiHk. oj; matlicrn. AIVI. VII. 2. 



31 



