6 ARKIV FÖE BOTANIK. BAND 17. N:0 1. 



Danaeopsis fecuiida n. sp. (Pl. 1, figs. 1—13.) 



Frond pinnate; pinnae narrowly lanceolate-linear, with 

 a rounded non-decurrent base, gradually tapering towards 

 the apex, 10 cm. long or more, at least 2,5 — 3 cm. broad a little 

 above the base. Scondary veins usually forking immediately 

 on leaving the midrib, distant about 1 mm. half-way to the 

 margin, forking again near the margin and the branches ana- 

 stomosing. Fertile pinnae, with the lower side, except the 

 midrib, completely covered ^vith contiguous sporangia. Each 

 sorus consisting of a double row of free, ellipsoidal sporangia 

 which have a faint longitudinal furrow marking the line of 

 dehiscence and a slight rounded depression at the apex; di- 

 mensions of sporangia 0,80 — 0,90X0,65 — 0,75 mm. 



The best specimen is the fertile pinna shown in pl. 1, 

 fig. 2. Only the upper part is preserved, the broken lower 

 end having a breadth of 3 cm. The specimen consists of an 

 impression of the upper side, the midrib occurring as a slightly 

 depressed band, 2 — 3 mm. broad, covered with a dark film of 

 carbonaceous matter. With the exception of the midrib, the 

 whole surface of the impression is completely covered with 

 the carbonized remains of the sporangia. These are very 

 well preserved, with the outward shape but little altered. 

 They are so closely packed that both the sporangia of each 

 row and those of different rows are in close touch with one 

 another, the sporangia being in fact often compressed through 

 want of space (pl. 1, fig. 4). 



The individual sporangia are ellipsoidal, but often appear 

 shorter than they are, because they have been compressed 

 parallel to the longer diameter. Though the sporangia are 

 very closely packed, they are not fused to form synangia, but 

 are free from each other right down to their bases. This is seen 

 on another, more fragmentary, specimen, of which a photograph 

 is reproduced in pl. 1, fig. 13. In this specimen the sporangia 

 themselves have disappeared with the exception of their bases 

 which appear as dark rings on the lighter surface of the rock. 

 In some places it can be seen that each ring has a complete 

 unbroken outline distinct from those of adjacent sporangia. 



At the apex of each sporangium there is a slight rounded 

 depression, not very sharply circumscribed but always distinct. 

 It is no doubt this hollow that has been taken for a pore by 



