HALLE, ON THE SPORANGIA OF SOME MESOZOIC FERNS. 5 



Rande verlaufend, rundlich, durch einen senkrechten Riss(?) 

 wie bei Ängiopteris, oder einen Perus (?) wie bei Danaea sich 

 öffnend». 



SoLMS Laubach (1887, p. 153) points out that new exami- 

 nation is wanted to decide whether Danaeopsis marantacea 

 should be brought to the Danaeaceae. He states that the sori 

 of the fossil form agree fairly well with those of Danaea, and 

 that, according to Schimper's figures, they seem to open by 

 pores, but that it is doubtful whether the sporaniga are fused 

 or not. 



PoTONiÉ (1899, p. 90) mentions Danaeopsis as agreeing 

 closely with Danaea in respect to the sori and sporangia. 



Leuthardt (1904, p. 29), who described new material 

 of Danaeopsis marantacea, confirms the statement that the 

 sporangia are fused to form synangia which open by pores. 



Krasser places his Pseudodanaeopsis under the subordo 

 Danaea which is characterized by the fusion of the sporangia 

 into synangia which open through apical pores. He com- 

 municates, however, Stur's diagnose of the fine material 

 from Lunz which Krasser identifies with Ps. plana (Emmons) 

 Font. (= Ps. reticulata Font.); and this diagnose gives a 

 different interpretation of the soral structure: »Sporangia 

 0.7 mm circiter longa, ovalia, basi latiora, apice acutiora, 

 oculo inermi laevia armato autem reticulata, rima extrorsa 

 dehiscentia, libera et basi tantum in receptaculo licet nervo 

 sessilia, seriata, et quidem in series duas, nervo fertili per 

 totam ejus longitudinem oppositas cum eodem parallelas 

 coordinata ». 



It will be apparent from this short summary of the dif- 

 ferent opinions that the structure of the sori and sporangia 

 of Danaeopsis and its relation to the recent genera of marat- 

 tiaceous ferns are by no means clear. In 1911 I found at the 

 Rhaetic coal-mines of Billesholm in Scania several specimens 

 of a Danaeopsis and among them a fine fertile pinna. This 

 specimen shows the sporangia with unusual clearness. It 

 belongs to a new species, which I have called D. fecunda on 

 account of the abundant production of large sporangia. 



