PHYLLOTHECA DELIQUESCENS. 283 



referred to Phyllotheca on insufficient grounds. Our know- 

 ledge of this Equisetaceous plant has recently been extended 

 by Zeiller^ who has recorded its occurrence in the Coal- 

 Measures of Asia Minor associated with typical Upper 

 Carboniferous plants. The same author^ has also brought 

 forward good evidence for the Permian age of the beds 

 in Siberia and Altai, where Phyllotheca has long been 

 known. It is true that Zigno's species of the genus occurs in 

 Italian Jurassic rocks, but on the whole it would seem that 

 this genus is rather a Permian than a Jurassic type. The 

 species which Zeiller describes under the name Phyllotheca 

 Rallii from the Coal-Measures of Herakleion (Asia Minor) 

 shows some points of contact with Annularia. It is much 

 to be desired, however, that we might learn more as to the 

 reproductive organs of this member of the Equisetales ; until 

 we possess a closer acquaintance with the fructification we 

 cannot hope to arrive at any satisfactory conclusion as to the 

 exact position of the genus among the Calamarian and Equi- 

 setaceous forms. M. Zeiller^ informs me that his specimens of 

 P. Rallii, which are to be fully described in a forthcoming work, 

 include fossil strobili resembling those of Annularia radiata. 

 The verticils of linear leaves fused basally into a sheath agree 

 in appearance with the star-like leaves of Annularia, but in 

 Phyllotheca Rallii the segments appear to spread in all directions 

 and are not extended in one plane as in the typical Annularia*. 



1. Phyllotheca deliquescens (Gopp.). 



In an account of some fossil plants collected by TchikatchefF 

 in Altai, Goppert^ describes and figures two imperfect stems of 

 an Equisetum-like plant. Owing to the apparent absence of 

 nodal lines on the surface of the stem the generic name Anarthro- 

 canna is proposed for the fossils ; and the manner in which the 

 main axis appears to break up into slender branches suggested 

 the specific name deliquescens. SchmalhauHen* afterwards 



1 Zeiller (952). 2 jj/j. (9(5). » Letter, July 80, 1897. 



* On this character of Annularian leaves, vide p. 887. 



6 Goppert (45) p. 379, Pl.xxv. figs. 1, 2. « Sohmalhausen (79) p. Vi. 



