32 INTEODUCTION. 



Anomozamites bifida (Heer) = ? NiUsonia tenuinervis, Ifath. 



£quisetites, sp. ; cf. JSquisetites columnaris, Brongn. 



Podozamites laneeolatus (L. & H.) = ^ Fodozamites lanceolatus. 



Ginkffo digitata (Brongn.) -j 



G. Suttoni (Sternberg) 1= Ginkgo digitata (Brongn.). 



<?. integriuscula,, Heer J 



Finns prodromus, Heer; cf. CzekanowsMa Murrayana (L. & H.). 



Stenorraehis striolatus (Heer) ; cf. Ginkgo, sp. (male flower). 



A few plants wliioli suggest the same geological horizon as that 

 of the Cape Boheman heds have been described also from Sassen Bay ; 

 the specimens referred by Nathorst to Nilssonia cf. orientalis, Heer, 

 may be compared with the English species N. tenuinervis, Nath. 



The Mesozoic plants obtained from Advent Bay and Cape 

 Staratsohin in Spitzbergen belong to a somewhat higher horizon, 

 and bear a close resemblance to Wealden types ; they are probably 

 of uppermost Jurassic age.' 



In a paper published in 1890 Schenk^ describes a species of 

 Araucarioxylon and two species of Cedroxylon from the plant-beds 

 of Grreen Harbour ; the specimens were originally described by 

 Cramer under the generic name Pinites? 



2. SlBEEIA. 



Among the Mesozoic floras of the far North the most important, 

 from the poiut of view of the distribution of Lower Oolite species, 

 is that which Heer has described from material collected by 

 Czekanowski, Hartung, and others. The principal localities at 

 which these Jurassic plants were discovered are Ust-Balei, in 

 latitude 51° N., about forty miles north of Irkutsk, the Upper 

 Amoor Eiver, the Lena district, and elsewhere.* 



Thyrsopteris Murrayana (Brongn.) \ 



T. Maakiana, Heer I ~ "" (^"'^'■"P*^^ hymenophylhides 



Dioksonia clavipes, Heer ( (Brongn.). 



D. arctica, Heer ' 



Asplenium whitbiense (Brongn.) = Toditea Williamsoni (Brongn.) and (pars) 

 ? GladophUbis dentimlata (Brongn.). 



' Vide Heer and Nathorst, loc. cit. 



2 Schenk (90). 



» Cramer, in Heer (68). 



♦ Heer (77') (78) (83'). 



