42 CONTRIBUTIONS TO GENERAL GEOLOGY, 1913. 



a small later collection, was studied by Fontaine, who was somewhat in doubt as to whether 

 it was Jurassic or lowest Cretaceous, the final compromise being to call the beds Jurasso- 

 Cretaceous. I have long regarded the material as of Jurassic age, and the critical study of 

 the ColUer collection a])poars to have proved this assignment beyond reasonable question. 



Of the 17 species from the Cape l.,isburne region noted in the jjresent pajjer, the folio whig 

 also occur in Amurland, eastern Siberia: Coniopteris iurejensis, C. hymenopJiyUoides, Podo- 

 zamitfs 1/incfolatvs, P. I. ricJiwalcIi. Phaiiicopsis spcciosa, P. angnstifoUa, Giril-ffo cligitaia, and 

 Pityophyllum nordenskioldi. These Amurland beds were regarded by Ileer as belonging to 

 that portion of the Middle Jurassic (Brown Jura) kno^\^l as the Bathonian, and so far as 

 kno^^Ti to me, this assignment has not been disj^utod. Seward in his late ])aper says: '"The 

 flora as a whole agrees closely with richer collections from ^fiddle Jurassic strata." 



In 1S76 Heer ' described a large number of Jurassic plants from the Government of 

 Irkutsk, eastern Siberia, and in 1911 Seward and Thomas - reported on a small collection from 

 the JJalagansk district, in the same province. After making allowance for the changes in 

 nomenclature there appear to be in these Irkutsk collections the follo^ving species in common 

 with those from Cape I.,i.-;burne: Coniopteris hurrjensisf, Ginl-go digitata, Phcenicopsis speciosa, 

 P. (ingiisti/olia, Podozamitcs lanceolaius, P. I. cichwaldi, and Klatides curi'ij'olia. 



A large collection of plants, in the main very well preserved, from beds regarded as of 

 Bathonian or lowest Callovian age, near Kamcnka, district of Izium, Government ol Khar- 

 kow, was described by Thomas'' in 1911. The following species from Cape Lisburne are 

 represented hi this flora: Coniopteris hymenophylloides, Chdophleiis Tiuttoni, Ginkgo digitata, 

 Klatides curriJoJia, Otozaniites glganteus, and Podozandits laneeoJatus. 



A small collection embracing 14 species from the western border of Mongolia, in Cliinese 

 Dzungaria, was described by Seward'' in 1911. The Mesozoic strata of this region, accordmg 

 to Obrutschew, who collected the plants, reach the enormous estimated thickness of 3,500 

 meters, thus a])])roaching the thickness recorded by Collier for the Cape Jjisburne region. The 

 following species are common to the two localities: Coniopteris hymenophylloides, Ginkgo digi- 

 tata, Plumicopsis angvsllfoUa, and Podozamitfs lanceolaius. On the basis of the jilants the 

 beds are correlated by Seward with the Middle Jurassic rocks of England and other parts of 

 the world. Seward calls attrition to the "remarkable resemblance between Rha-tic and 

 Jurassic floras as regards general facies," and adds: '"It appears to be certain that some types 

 persisted from the Rha^tic ])eriod to the middle or even to the latest stage of the .Jurassic era." 

 This resemblance will 1)0 alluded to later. 



Seward '' has dcscribcHl a small flora from Caucasia and Turkestan, from beds of Middle 

 Jurassic age or older, which includes the following species found also at Cape I^isburne: Coniop- 

 teris hymenophylloides, Podozamites hnceolatus, Ginkgo digitata, ami Phanicopsis angustifolia. 



In 1S76 Heer" described over 30 species of plants from the vicinity of Cape Boheman, 

 Spitzbergen. The beds in which they were found were regarded by Heer as belonging to the 

 Brown Jura (Bathonian), and Nathorst,' who revised the flora in 1X07, then conlirmed tliis 

 position, but later' he |)rocured evidence which induced him to regard the age as near or 

 above the Oxfordian that is, in the U])per or White Jura. Tiie species from Cape Boheman 

 represented in the rocks of (^ape Lisburne are Podozamites lanceolaius, P. I. eichwaldi, Ginkgo 

 digitata, PJianicopsis angustifolia, and Pityophtjlhiiu nordenskioldi. 



In the ])aper last cited Nathorst also enumerates anew the Upper Jurassic plants from 

 Advent Bay, Spitzbergen, Fitldenia nordenskioldi and Klatides curcifolia Itcing in common 

 with Cape Lisburne. The flora of Franz Josef Land, regarded by Nathorst as younger than 



' Ilcer, Oswald, Floni fo.'tsilis aroticn, vol. 4, pt. 2, pp. 28-S<(, 1876. 



• Com. gik)l. Mi'm., new sor.. pt. 73, 1811. 

 > Idem, pt. 71, 1011. 



« Idem, pt. 75, 1911. ' 



' Idem, pt. :)S, 1907. 



• llccr, Oswald, Flora fassIUs arctica, vol. i, pt. 1. pp. 211-47, IS77. 



' Nathorst, A. Ci., Koncl. Svcnska Vetonskaps-Akad. llandl., vol. 30, p. 6, 1897. 



• Nathorst. \. Ci.. Fossil jilanl* from Franz. Josef Land: Nonvc|{ian North Polar F.xped.. vol. 1, No. .1, 1900. 



