233 



j-ears by Raoiborski and Staub. The former autbor, in his Fossil 

 Flora of the Craooio District, describes several species of Ctenis,^ 

 some of which exhibit circular projections on the surface of the 

 segments similar to those noticed by Sohenk. The epidermal cells 

 •of the segments bear several circular projections which Eaciborski 

 regards as sori or sporangia, and accepts as evidence of a Filicinean 

 affinity ; he was, however, unable to recognize any actual sporangial 

 structure. In a recent paper by Staub ^ on species of Ctenis, an 

 unusually large frond of Liassio age, reaching a length of 2 metres, 

 is described under the name Ctenis hungarica ; on the segments 

 of this frond were found small depressions which the author of the 

 species speaks of as sori. "We see, then, that the inclusion of 

 Ctenis among the ferns rests on inconclusive evidence, and no proof 

 has been adduced that the circular elevations or depressions on 

 the epidermal cells are of the nature of sori or sporangia. 



In his Floran vid ^M/Nathorst^ described some long and broad 

 leaves with reticulate venation, which he referred to a new genus, 

 Anthrophyopsis, on account of their resemblance to the simple 

 fronds of the polypodiaceous iera. Anthrophyum. In 1879 Xathorst 

 transferred these Ehsetio specimens to the genus Ctenis, the supposed 

 leaves being recognized as detached and fragmentary segments of 

 ■a pinnate frond. Some of the figures of the Scanian fossils show 

 circular elevations on the epidermis like those already referred to. 

 My own observations lead me to regard the evidence hitherto relied 

 on in favour of placing Ctenis among the ferns as insufficient, and 

 I believe the general habit of the leaves is a strong argument 

 for including the species of this genus among the Cycadales. 

 A specimen in the Manchester Museum from the Yorkshire coast 

 rocks was described by Ifathorst'' in 1880 as probably a new species 

 ■of Anthrophyopsis ; a recent examination of this specimen has 

 afforded important information as to the nature of the supposed 

 sori described by Eaciborski, Sohenk, E'athorst, and Staub. The 

 specimen (Text-fig. 42) consists of a portion of a pinna 9 cm. in 

 length and 2"6 cm. broad, traversed by short parallel veins which are 

 •connected here and there by oblique transverse veins ; the epidermal 



' Eaciborski (94), p. 31, pis. xvi.-xviii. 



■ Staub (96). 



3 Nathorst (78>). 



* Xatborst (80'), p. 83. 



