Prof. 0. Ileer on the Miocene Flora of the Polar Regions. 61 



Fig. 2. Portion of the same, enlarged : showing the solid axis, the com- 

 mon canal, and the cellules. 

 Fig. 3. Transverse section of Diplograpsus terethisculus, His. : showing 



the axis as a transverse plate or partition. 

 Fig. 4. Dijjlograpsus teretiu senilis, His., nat. size; showing the proximal 

 extension of the axis, or radicle (a), and the distal extension (h). 

 Fig. 5. Central portion oi Didiograpsns Logani, Hall, sp., fi-om a speci- 

 men collected by the author from the Skiddaw Slates : show- 

 ing the branched funicle and the celluliferous stipes. 

 Fig. 6. Central disk and funicle of Dichograpsus octobfachiaius, Hall, 

 sp. One of the divisions of the funicle (a) is shown prolonged 

 into a celluliferous style (6). 

 Fig. 7. Diplograpsus, n. sp. : showing a disk at the proximal extremity. 



Collected by the author at Garple Linn, near Moftat. 

 Figs. 8, 9, 10. Varieties of Diplograpsus bicornis, Hall. Fig. 8. Normal 

 form. Fig. 9. Variety with a rudimentary disk or cup ; col- 

 lected by Prof. Harlmess at Glenkiln Burn, Dumfriesshire. 

 Fig. 10. Variety with a fully developed disk, after Hall. 



Fig. 11. Diplograpsus vesicidosus, n. sp. : showing the distal extremity of 

 the axis expanded into a pointed vesicle. Collected by the 

 author at Dobb's Linn, near Moffat. 



Fig. 12. Germ of a monoprionidian Graptolite, enlarged. 



Fig. 13. Germ of a diprionidian Graptolite, enlarged. 



Fig. 14. Didymograpsus Jlaccidus, Hall, nat. size (recently described by 

 Mr. W. Carruthers imder the name of D. elegans). This form 

 could obviously never have been attached, but must have been 

 free. 



Fig. 15. Helicograpsus (Graptolithus) gracilis, Hall, sp., nat. size: c, 

 fimicle : b, b, celluliferous stipes. From a specimen collected 

 by the author at Glenkiln Burn, Dumfriesshire. 



Fig. 16. Non-celluliferous stem, or funicle, of Dendrograpsus Hallianus, 

 Prout, after Hall. This species may perhaps have been 

 attached. 



Fig. 17. Portion of the celluliferous branches of the same. 



Fig. 18. Diplograpsus resembling D. teretiusculus, His., but furnished 

 with two lateral spines in addition to the central radicle. 



Fig. 19, Corynoides caliadaris, Nich., enlarged. This form is allied to 

 the Graptolites, but probably represents a different order. 



Fig. 20. Tetragrapsus qicadribrachiatus, Hall, sp. : showing the funicle, 

 radicle, and celMiferous stipes. 



X. — On the Miocene Flora of the Polar Regions. 

 By Professor O. Heer *. 

 The numerous expeditions sent some years ago into the 

 arctic regions have been, in every respect, productive in a 

 scientific point of view. The bold navigators who explored 

 the polar regions, surmounting the greatest difficulties, used 

 every effort to bring back whatever they supposed might pos- 

 sess interest. Geology has had its share in the results of 

 these researches. A considerable number of fossil plants 



* Translated by W. S. Dallas, F.L.S., from the ' Bibliotheque Univer- 

 selle,' Archives des Sciences, Nov. 25, 1867, pp. 218-231. 



