6 HALLE, ON THE SWED1SH SPECIES OF SAGENOPTER1S PRESL AND ON HYDROPTERANGIUM NOV. GEN. 



In pl. 1, figs. 15—17 I have redrawn the type specimens of S. dentata Nath. 

 Though the teeth of the margin are deeper and more acute than is generally the 

 case in S. undulata, there is hardly any doubt that the specimen fig. 15 should be 

 included under that species. The margin of the outer leaflets of S. undulata is, in 

 exceptional cases, also provided with teeth of the same aspect. An example of this 

 is seen in pl. 1, fig. 1 a, representing the basal portion of a pinna of a typical S. 

 undulata. 



The specimens figs. 16 and 17 do probably not at all belong to Sagenopteris. 

 In the shape of the marginal teeth, as well as in the reticulate venation, there is a 

 great resemblance to the specimen fig. 15, but the structure of the epidermis is quite 

 different. The stomata of the lower side are smaller, of a different shape and ar- 

 ranged in well defined rounded groups, bordered by tangentially elongated cells. The 

 same very peculiar structure is seen in the epidermis of Ctenis and possibly both 

 these specimens may be referred to that genus, though differing as to the dentate 

 margin. It is notewortly also, that the veins are more parallel than in Sagenopteris 

 and somewhat suggestive of the venation of Ctenis. 



S. undulata comes very near to S. Phillipsi (Brgn.) Stbg. From that species 

 it differs mainly in the constantly undulating or dentate margin of the fully devel- 

 oped pinna?. As a rule these are also narrower and their apices more acute and 

 elongated. Small leaves sometimes recall S. angustifoUa Zign. as figured by Zigno 

 (1, pl. 20). 



S. undulata has hitherto only been found at Bjuf, in the plant-bearing layers 

 1 and 3, and at Höganäs in the lower plant-bearing beds. As far as I know, it has 

 not yet been recorded from any locality outside Sweden. 



Some few and badly preserved specimens of a Sagenopteris from Hyllinge may 

 possibly belong to this species, but the poor quality of the material does not permit 

 of a specific determination. 



Sagenopteris Nilssoniana Brgn. sp. 



(Pl. 1 fig. 24; pl. 2 figs. 15—23; pl. 3 figs. 6 — 11.) 



1820. - Sv. Nilsson (1). P. 8; pl. 5, figs. 2, 3. 



1824. Mlicites Nilsoniana A. Brongnurt (1). P. 218; pl. 12, fig. 1. 



1828. Grlossopteris Nilsoniana A. Brongniart (2). P. 54. 



1828. Grlossopteris Nilsoniana A. Brongniart (3). P. 225; pl. 63, fig. 3. 



1838. Sagenopteris rhoifolia Presl (1). P. 165; pl. 35, tig. 1. 



1876. Sagenopteris rhoifolia Presl. Nathorst (1). P. 31; pl. 1. figs. 2—5. [German edition Nathorst (2) 



1878. P. 17. | 



1878. Sagenopteris rhoifolia Presl. Nathorst (3). P. 11. 



1900. (?) Sagenopteris Nilsoniana Brgn. sp. Wahd (1). P. 352; pl. 56, tig. 1; pl. 67. tig. 2. 



As complete lists of the synonymes of this species have recently been given by 

 Möller (1, p. 56) and S alfeld (1, p. 17), I have referred only to some more im- 

 portant data. That the fossil, figured without narae by Nilsson 1820 and låter on 



