KUNGL. SV. VET. AKADEMIENS HANLIDNGAR. BAND 51. N:0 3. 25 
> 
whether HBER'S fig. 15 gives a true idea of its venation. Having due regard to the 
great resemblance between the Patagonian and the Greenland specimens, it seems best, 
under these circumstances, to describe the former as Gleichenites ef. micromerus. 
There is a fairly great resemblance to smaller fragments of Gleichenites bindra- 
bunensis SCHIMP. (OLDHAM & MORRIS 1863, p. 45; pl. 25; pl. 26, figs. 1, 3 [as Pe- 
copteris gleichenoides n. sp.]; — FEISTMANTEL 1877 a, p. 41) from the Rajmahal Group 
of the Indian Gondwanas, but it does not appear to be so close as to the Green- 
land species. 
The present specimen was found in locality c. 
Cladophlebis australis (MORRIS) SEWw. 
PI. 1, figs: 10—13. 
Pecopteris FORS Morris 1845, p. 248; pl. 7, SR IR: 
> NIECOxe Not Ip: LGs pl 14) fig. 
Alethopteris — » FEISTMANTEL 1878, p. 109; pl. 14. 13 Lå 
» » TENISON-Woops 1883, p. 111. 
» concinna TENISON-Woops 1883, p. 112; pl. 9, fig. 1. 
Todea australis RENAULT 1883, p. 81; pl. 11, figs. 1-—5. 
Cladopluebis denticulata Brons. var. australis SEWARD 1904 a, p. 171; pl. 16, figs. 25—27 
A few specimens of detached pinnae of the Cladophlebis denticulata-type have 
been found in the plant-bearing slate of Rio Fösiles. They appear to show a close 
resemblance to the form described by MORRisS (Il. c.) as Pecopteris australis and may 
be referred to as Ciadophlebis australis (MORRIS) SEW. 
Figs. 10, 11, pl. 1, show the best specimens, both of them only fragmentary 
pinnae. "The pinnae appear to have been linear in shape, with slender rachises. The 
pinnules are fairly closely set and directed obliquely forwards. They are linear, with 
the edges in the larger part almost perfectly parallel and the apex short and bluntly 
pointed. The midrib is slender, somewhat flexuous in the upper part, and splits up 
just before reaching the apex. The lateral veins, which form a narrow angle with 
the midrib, are very fine. They divide only once or, at the base of the pinnule, 
sometimes twice, their branches being straight and parallel. 
Sterile fern-fronds of this type are of common occurrence in Jurassic and Lower 
Cretaceous rocks. To group such fronds into definite species of taxonomic value is 
impossible, but certain types have been recognized and referred to, by some writers, 
under separate provisional names. The fossils which come nearest to the Patagonian 
fronds are certain specimens identified with Pecopteris australis MORRIS (1. c.). Especi- 
ally the fine frond figured under this name by M”CoY (1. c.) and refigured by FEIST- 
MANTEL (1. c.) as Ålethopteris australis bears a great resemblance to the present speci- 
mens. Of Morris” type-specimens, on the other hand, at least one is different, the 
enlarged drawing of a pinnule given by MORRIS (fig. 2a) showing a regular double 
bifurcation of the secondary veins. MORRIS remarks, however, that the veins divide 
once or twice. M'Coy's specimen may therefore be referred to MOoRRiS” species and 
EK. Sv. Vet. Akad. Handl. Band 51. N:o 3. 4 
