KUNGL. SV. VET. AKADEMIENS HANDLINGAR. BAND 45. NJO 7. 11 



Hydropterangium nov. gen. 



Capsules, dorsiventral, flattened from the sides, oblong or bean-shaped, borne 

 by pedicels, attached to one end of the capsule. Each lateral half traversed by 

 ridges, parallel or diverging from the median portion of the dorsal edge. 



Hydropterangium marsilioides n. sp. 



(Pl. 2, figs. 1 — 14; pl. 3, figs. 12—15.) 



The capsules referred to under this provisional name may belong to two differ- 

 ent species of plants, as there is some difference in shape and size between the 

 specimens of the two localities, Bjuf and Hyllinge. The material is, however, not 

 suff icient to justify a specific separation ; this is also a matt er of minor importance. 

 In regard to the undeniable difference, the specimens from each locality will, however, 

 be described separately. 



The specimens from the black slate of Bjuf (pl. 2, figs. 1, 2) represent flattened 

 impressions of the capsules, 5—8 X 4 — 5 mm. in size. In the specimen fig. 1 are 

 seen the ridges traversing the side of the capsule. In the grey clay of the same 

 locality (layer a) the mode of preservation is somewhat different. Beside impres- 

 sions, like those from the slate, there occur flattened casts of the interiör of the 

 capsule. Such casts are shown in figs. 10 — 11, pl. 2. They show on the surface 

 transverse ridges and furrows like those on the impressions in the black slate. The 

 casts are coated by a thick layer of coal, representing the tissue of the capsule-wall. 

 Specimens like these show that the objects were really hollow bodies and not some 

 kind of scale-fronds, as might have been suspected from the flattened specimens in 

 the slate. 



One of the specimens occurring in the grey clay of Bjuf (pl. 2 figs. 6 — 8) 

 affords a peculiar interest. It shows clearly an impression of a capsule attached to 

 a pedicel. As seen in the figures, the pedicel joins the capsule at one end. This is 

 of some consequence, as the ridges and furrows and certainly also the veins of the sides 

 of the capsule radiate from the dorsal edge and not from the end. It seems, therefore, 

 as if the bundle, entering from the pedicel, followed for some distance the margin of 

 the capsule before splitting up into transverse secondary branches. In this respect there 

 is a striking resemblance to Marsilia, and, in fact, the photograph fig. 8, pl. 2 could 

 equally well represent a sporocarp of a living species of that genus. The pedicel has 

 in this specimen a length of 27 mm. The counterpart is seen in fig. 7. It would 

 almost seem from this impression, as if the pedicel branched at the knee, seen a little 

 below the capsule, but the specimen gives no sure information on that point. Another 

 specimen with a less distinctly defined pedicel is shown in fig. 9, pl. 2. 



The specimens from Hyllinge are larger than those from Bjuf and possibly 

 represent another species. That they are of the same morphological nature can 



