4 ARKIV FÖR BOTANIK. BAND 17. N:0 1. 



matopteris because it has large sporangia covering the whole 

 lower surface of the pinnae. He remarks on the absence of 

 any sign of a pore or an annulus. In a later paper (1864 a, 

 p. 34) he again mentions the difference between this type and 

 Taeniopteris and points out the very close agreement with 

 the genera Danaea and Angiopteris in regard to the habit and 

 the venation. 



Heer, who mentions the new name Danaeopsis for the 

 first time in his »Urwelt der Schweiz» (1864, p. 54; pi. 2, fig. 5) 

 does not give any description of the sori or sporangia in that 

 place, beyond mentioning that the frond on its lower side is 

 covered with globular sporangia placed in two rows. In his 

 »Flora Fossilis Helvetiae» (1876—77, p. 71, pi. 24, fig. 1) he 

 gives further illustrations of the sporangia and discusses the 

 affinities of the genus. The sporangia of Danaeopsis are stated 

 to be biseriate, placed in linear sori which are inserted on 

 the veins. He is not able to decide whether the densely placed 

 sporangia are really fused, as in Danaea; but he thinks that at 

 any rate the fusion cannot be so close as in that genus, because 

 the individual sporangia can always be clearly distinguished. 

 In his description of the species D. marantacea, the sporangia 

 are stated to be globular, exannular, and to open by a trans- 

 verse slit. The rows of sporangia are placed two and two, 

 but each pair of rows is not »surrounded by a receptaculum», 

 as in Danaea, this being a difference between the fossil and 

 the living genus. In habit and venation the species is stated 

 to recall Danaea, also in the fact that the sporangia are placed 

 in two closely approached rows, which follow the secondary 

 veins from the midrib to the margin, while in Angiopteris 

 they only form a band along the margin. In regard to the 

 shape of the frond, to the venation and the arrangement of 

 the sori, Heer further compares Danaeopsis marantacea with 

 the recent species Gymnogramme javanica, which, however, is 

 recognized as having smaller and differently arranged spor- 

 angia. 



ScHiMPER in liis »Traité de paléontologie végétale » gives 

 a diagnosis of the genus in which the sporangia are said to be 

 uniseriate, but nothing is stated in regard to the mode of de- 

 hiscence or the relation to Danaea. The »Palaeophytologie» 

 (1879 — 1880, p. 88) contains the following remark on the spor- 

 angia: »Sporangien in dichtgedrängten Reihen bis zum 



