257 



small-celled filaments radiating towards the centre. In a vertical section these fila- 

 ments are only little conspicuous, and there are only feeble rudiments of papillae 

 in the conical orificium (fig. 177). One to four layers 

 of vegetative cells are to be found under the concep- 

 tacles. 



The antheridial conceptacles are small, sometimes 

 entirely immersed, usually, however, more or less pro- 

 minent. The inner cavity has a flat bottom, and may 

 be about 40// in diameter. The ostiole is not prolonged 



in a spout. 



A, vertical 



Fig. 176. 

 Melobesia microspora. 

 section of ttiin crust. B, surface view 

 of crust near the border. C, basal 

 layer seen from the face, showing 

 numerous fusions. 350:1. 



'to 



B 



The spermat- 

 angia form a 

 covering on 

 the bottom of 

 the concep- 



tacle ; they are produced from small 

 squarish or trapezoid cells, and are 

 lengthened, upwards incrassated, some- 

 times a little curved cells. Sometimes 

 the spermatangia are produced not di- 

 rectly from the small squarish cells but 

 from cells of the same shape as them- 

 selves (fig. 178 C at left). The spermatia 

 are clavate, broadest in the upper end, 

 sometimes slightly curved, about 6 fj. long, 

 and 2u broad at their broadest end, (fig. 

 178 C). Under the bottom of the con- 

 ceptacles up to 5 layers of vegetative cells 

 may be found. 



Of female conceptacles I have only 

 met with very few, which gave no clear 

 idea of their structure. They seem to be 

 similar in shape and structure to the 

 sporangial ones. Fig. 179 shows a con- 

 ceptacle containing carpogonia and tri- 

 chogynes; at left is shown a carpogonium 

 from another section of the same con- 

 ceptacle. 



This species seems to be quite di- 

 stinct from all well known species of the 

 genus. The want of cortical cells is in- 

 deed so remarkable as possibly to suggest 



D. K. D. Vldensk. Selsk. Skr., 7. RceUke, nytui vidensk. og mathciii. Afd. VII. 2. 33 



Fig. 177. 



Melobesia microspora. A, vertical section of sporangial 

 conceptacle with a tetrasporangium B, sporangial con- 

 ceptacle seen from above. C, emptied sporangial con. 

 ceptacle showing the rest of the columella. 350 : 1. 



Fig. 178. 



Melobesia microspora. A and B, vertical sections of frond 

 with antheridial conceptacles. C, spermatangia and sper- 

 matia. A and C 560 : 1, B 350 : 1. 



