KUNGL. SV. VET. AKADEMIENS HANDLINGAR. BAND 57. NIO |. 29 



move the cementing mineral matter and then with Schultze's mixture. The whole 

 mäss was found to consist of spores; and the same result was obtained at the examination 

 of other fragments from the same specimen. In the specimen in fig. 15 — which was 

 found låter, at the splitting of a piece of the slate — the spores can be observed without 

 any chemical preparation, if the whole piece is placed under a microscope with an objec- 

 tive of sufficient magnifying power: the brown spores, if sufficiently illuminated, con- 

 trast vividly against the black carbonized wall of the sporogonium seen in the figure. 

 In this specimen the whole upper part of the capsule appears filled up with spores. 



The spores of both specimens are perfectly similar: they measure 0,020 — 0,025 

 mm. in diameter and are of the tetrahedrally rounded type. Figs. 18 — 22 of pl. 3 repre- 

 sent a number of microphotographs of spores in different magnification. Fig. 18 shows 

 two dense masses of spores on which the acid has not been allowed to act long enough. 

 Tlie spores are not compressed as is so often the case in fossils, but retain their rounded 

 shape — probably because the mäss of spores has been incrusted with some ferruginous 

 substance. If seen in a certain position their outlines sometimes display three small 

 indentations suggesting the occurrence of pores or perhaps furrows (figs. 21 and 22); 

 these indentations have not been observed in surface view. At a very high magnifica- 

 tion the surface of the spores presents a fine dotted sculpture. — Though the spore-wall 

 is sufficiently cutinized to have resisted destruction during the long ages since the early 

 Devonian, it is very delicate. If, af ter treatment with Schultze's mixture, the spores 

 are placed in ammonia, or if glycerine is added in the usual manner, they will shrink and 

 finally crumble to pieces. The same is the case, in a still higher degree, if they are sub- 

 jected to alcohol as a preliminary to being mounted in Canada balsam. It was very 

 difficult therefore to obtain preparations that could be kept: most of the microphoto- 

 graphs in pl. 3 were taken while the spores were only kept in water. In lactic acid they 

 also retained the original shape fairly well. To obtain durable preparations the follow- 

 ing methods were used: to the water in which the spores were kept glycerine was added 

 very gradually — even then the result was not satisfactory — or they were allowed to 

 dry, whereupon they were brought into xylol, which was very slowly saturated with 

 Canada balsam. 



The specimen of the sporogonium which gives the best information on its structure 

 is the one shown in pl. 3, fig. 23, and enlarged in figs. 24 and 25. This specimen retains 

 the original shape more perfectly t han any of those already described. This, however, 

 holds true only for the capsule, which appears to be broken off from the stalk. Of the 

 latter no trace is seen on the first glance, but a careful examination of the rock surface 

 reveals a very faint yet unmistakeable line running for a distance of about 30 mm. from 

 the base of the capsule. That this line is real is confirmed by the fact that it runs straight 

 to and is continued by a short elevated streak of a ferruginous substance, which in this 

 kind of rock is a common form of preservation of fine branches. The capsule is elonga- 

 tedly obovoid, somewhat flattened, and measures 9 mm. in length by 3,5 mm. in maxi- 

 mum diameter. Towards the base it tapers gradually, as in the specimen in fig. 10, 

 which it recalls also in the basal striation: this striation here consists of 5 or 6 fine ridges 

 in the exposed half . A little above the middle of the capsule there are some marked longi- 



