j 

,_ 

DEPARTMENT OF THE INTERIOR 

UNITED STATES GEOLOGICAL SURVEY. 

GEORGE OTIS sMrra, DmEcTon 

PROF]l:SSIONAJ.- P Al."'ER .85-D 

THE 

J-URASSIC FLORA OF CAPE IjiSBURNE 

ALASK1t 

BY 

F. H. KNOWLTON 

PART D OF PROFESSIONAL PAPER 85, "CONTRIBUTIONS 

TO GENERAL GEOLOGY 1913" 

WASIIINGTON 

GOVERNMENT PRINTING OFFICE 

1914 
'.: 

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CONTENTS. 

Page_ 

·Introduction ____ ._. ______________________ .. 1 •••••••••••••••••••••••••••••••••••••••••••• _ ••• _. _.......... 39 

·The Corwin formation .... _ ...... _ ....... _ ... _ ................ _ ......... _ ................. _ ... _ ...... _ . . . . . 39 

·Plant collections ........................ _ ·. _ , .. : .. · ...... , . · .......... __ ...... : .. _ ...... : ................. ·. . . 40 

. Age of the plant-bearing beds __ ... _ .................................................. · . . . . . . . . . . . . . . . . . . . . . 41 

.Distribution of Jurassic floras ............. __ ... _._._._ ... _ ........ _ .............. · ....... _ .. _._............ 43 

Geographic range ......... _._ .... __ ...... ~ .......... _ ....... _ ... _ .............................. , .... .'. 43 

Means of disper&'tl ......... _ .............. : . ................................... ~ ........ ; . . . . . . . . . . . . 45 

Avenues of dispersaL ................................ : ........................ , ... ·................... 45 

Probable climatic conditions ....................... , ............ :. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 

'.The flora .............. ·.· ................................... ·............................................. 4u 

ILLUSTRATIONS. 

Pagu. 

PLATES V-VIII. Jurassic flora of Cape Lisburne, Alaska.·.· ................................................. 57-64 

II 

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··... . ·,· .. 

'"!"'HE JUH.ASSIC FLORA OF CAPE LISBURNE, AI~ASKA'.'' 

By F. I-I. KNOWLTON. 

INTRODUCTION. 

A peculiar anct'.absorbing interest attaches to the study of the fossil floras of the arctic 

regions, for they indicate clinuttic conditions very unlike those now existing in those regions. 

In place of the present· snow and ice and the scant, nhnost p~rpetually fro~en soil which supports but a hn.ndful of depauperate plants, the conditions fr:om at least late Paleozoic to 

1niclclle Cenozoic time made an abundant and luxuriant· vegetation possible, at least during 

certain periods. Although these lands are now so inhospitable, and hence but rarely visited, 

an astonishing amount of inform~tion concerning their fossil floras has been accumulated, 

ttnd to this knowledge Alaska has contributed its full quota, though doubtless much more 

will ultimately be known. 

The recent publicatio1,1 of a report by Prof. A. C. Sewn.rd on the Jurassic plants oi Amurlu.nd, long known fr01n the historic researches of Oswald Heer, has called to n1incl the existence 

of a, considerable collection of sinTilar plants fron1 the vicin~ty of Cape Lisburn~, Alaska, 

thn.t has been in n1y possession for a number of years. As it is now possible, with Seward's 

. paper in hand, to recognize still further the striking resmnblances between the Jurassic floras of 

Alitsk11 a,ncl Siberia, it seen1s an opportune time to present the results of this recent_ study. A 

preliminn.ry exmnination of this material was n1ade, and certain tentative ide~1tifications were 

adopted in a, short report for the use of the geologists who collected it, but ·this is the first 

tin1e it has been adequately described and figured. . · 

The 1nateri~tl considered in this paper was collected in 1904 by Arthur J. Collier1 of the 

United States Geological Survey, while engaged in a study of the geology .and coal resources 

of the Cape Lisburne region. 1 The coal deposits a.re extensive- and are the· only. mineral resources of the region known to be of commercial in1portance. Collier describes the locality as 

follows: 

Ca.pe Lisburne is the bold headland which marks the northwestern· extremity of a. land mass projecting into 

tJ10 Arctic Ocea.n from tJ1e western coast of Alaska between latitudes 68° m~d 69~. It lies 160 miles north of the 

Arctic Circle, about 300 miles directly north of Nome, and is the only point in Alaska north of Bering Strait where 

hills a.bove 1,000 feet in height approach the sea. · · 1 

So far as known, the rocks of the Cape Lisburne region are all sediment~!Y· The age 

represented, with the approximate thickness of each, is given by Collier as ·follows: Devonian ( ~), 

2,000 + feet; Lower Carboniferous [Mississippian], 4,500 + feet; Upp,er Jurassic, 15,000 + feet; 

Lower Cretaceous ( ~), 10,000 + feet; Pleistocene, 50 feet. · ·· 

THE CORWIN FORMATION. 

f! I 

The Jurassic section to which the name Corwin forn:ut·tion: ·has. been given is· described by 

Collier 2 a,s follows: ) 

~~~he older of the Mesozoic formations, which takes its name froril1 C~rWiiimlufi··and the.cmil mines th·~re loca.ted, 

is best exposed on tJ1e coast at a point 26 miles east of Cape Lisburne and. tlleJ~ce extends Iior.the.ast,vard to iCape Beaufort, a distance of 40 miles, which is tJ10 limit of tl1is investigation. It is known to occur again near Wainwright Inlet 

1 U. S. Gcol. Survey Bull. 278, pp. 1-54, Pis. I-IX, 1906. 2 Op. cit., p. 27. •, 1 I' 

39 
40 CONTRIBUTIONS TO GENERAL GEOLOGY, 1913. 

100 miles beyond Cape Beaufort, and there is some reason for the belief that it is continuous to that point. The southern 

boundary of 1J1e formation extends in a southeasterly direction from the coast for about 12 miles, when it turns to the 

south. Beyond this tile inland extension of the formation has not been determined. * * * 

No contact between the Corwin formation and the Carboniferous [later determined to be in part Triassic] rocks 

described occurs witllin the limits of the area under investigation, though an unconformity is evident ·from certain 

bed~ of conglomerate containing pebbles derived from the Carboniferous. Lithologically the formation consists of 

rather thllily bedded shales, sandstones, conglomerates, and coal beds. Fossil plants occur in the shales wherever 

they have been closely examined. * * * The formation throughout presents very little variation in lithologic 

character beyond the fact that in some portions of the section the shales are more carbonaceous, while in others they 

are more calcareous. Throughout the section there is nearly the same proportion of sandy beds. 

As alreadymdicated, the Corwin fonnation reaches the enormous thickness of over 15,000 

feet and contains forty to fifty coal beds which range in thickness fron1 1 or 2 to over 30 feet, 

ten being over 4 feet thick and suitable for n1ining, the whole aggregating at least 150 feet. 

PLANT COLLECTIONS. • 

The plant material obtained frmn the Corwin formation is con~prised in :nineteen collections, 

from as many localities,, qistributecl along the coast from Corwin Bluff to Cape Beaufort, a 

distance of about 140 miles and apparently representing beds at different horizons throughout 

the formation. So far as the data at hand indicate, there is little or no variation in the flora 

through the whole thickness of the fonnation. When the .preliminary examination of this material was made, and without knowing the relative stratigraphic position of any of the collections, 

a tentative attempt was made to fix the position in the section of a few of the lots. This attempt., 

however, was a failure, for certain collections which it seemed probable belonged near the base 

were in reality well distributed through the section and, for the present at least, the flora must 

be considered as a unit. As Collier has well said, "It is reasonable to expect some changes in 

the flora from the base to the top of a formation of such great thickness, but in this case the 

variation, if it exists, will probably be detected only by the paleobotanist after a critical personal examination of the section." 

As Collier's collection was not the first to be made in the Cape Lisburne region, a brief 

review of previous collections and the age determinations given to them may be of interest. 

Apparently the first to obtain material from the Corwin formation was A. Collie, who 

accompanied Capt. F. W. Beechey on his celebrated voyage to the Arctic. He first noted the 

presence of coal beds at Cape Beaufort and speaks of "carbonized impressions of reeds, both 

fluted and plain, generally flat," which were taken by William B~ckland/ who reported on the 

1naterial, as indicating Carboniferous. As already noted, Collier found only Jurassic at Cape o 

Beaufort. 

Nearly 50 years passed before anything further was known from Cape Lisburne. From 

1884 to about 1887 Henry D. Woolfe, while in the employ of .the Pacific Steam Whaling Co., 

made annual visits to the region and sent to the United States National Museum a considerable 

collection of fossil plants. This material was studied by Lesquereux, 2 who enumerated the 

following forms: 

Aspidium oerstedi Heer. 

Asplenium dicksonianum Heer. 

Asplenium foersteri Deb. and Ett. 

Baiera palmata Heer. 

Chondrites filiciformis n. sp. 

Irites alaskana n. sp. 

Pecopteris denticulata Heer. 

Pinus? staratschini Heer. 

Podozamites latipennis Heer. 

Zamites alaskana n. sp. 

· Lesquereux concluded that the age of the beds was probably N eocomian. 

In 1890 H. D. Dumars made a small collection of plants fron1 the Corwii1 coal mine, which 

came ultimately to the United States National 1\1useum. This collection, together with all of 

the Woolfe material, was elaborated by W. M. Fontaine for Lester F. Ward's monograph 

"Status of the Mesozoic floras of the United States." 3 Fontaine revised. and changed n1any 

1 Zoology of Captain Beechey's voyage, Geology, p. 173, London, 1839. 

2 U.S. Nat. Mus. Proc., vol. 10, p. 36, 1887; vol. 11, pp. 31-33, 1888. 

aU. S. Geol. Survey Mon. 4~, pp. 153-175, Pis. XXXIX-XLV, 1905. 

\ 

.I 
THE JURASSIC FLORA OF CAPE LISBURNE, ALASKA. 41 

of Lesquereux's detel'lninations and as a final result of his studies gave the following list of 

species: 

Chondrites filiciform.is Lesq. 

Dicksonia saportamt Heer. 

Onych.iopsis psilotoides (Stokes and Webb) Ward. 

Cladophlebis vaccensis Ward. 

Cladophlebis alata Font. 

Cladophlebis huttoni (Dunk.) Font. 

Podozamites distantinervis Font. 

Podozamites grandifol.ius? Font.· 

Baiera gracilis (Bean) Bun b. 

Ginkgod.ium? alaskense Font. 

Ginkgo digitata (Brongn.) Heer. 

Ginkgo huttoni (Sternb.) Heer. 

Ginkgo huttoni magnifolia Font. 

N ageiops.is longifolia Font .. 

Fontaine discussed this flora at some length, his final conclusion being stated as follows: 

"T'he age of the formation yielding the Alaskan fossils, as indicated by then1, is not older than 

the Lower Oolite and not younger than the Lower Cretaceous but is probably between then1." 

On the basis of this statement Ward called the Cape Lisburne plants "Jurasso-Cretaceous." 

In. the prelitninary study of Collier's material I took occasion to go over son1e of the identifications 1nade by Fontaine and felt obliged to dissent fron1 several of them. For example, 

the specin1en which Fontaine determined as Podozamites distantinervis Font., a well-known 

Potmnac species, I called P. Zanceolatus latifolius, a Jurassic for1n. It appeared that Fontaine's 

great familiarity with the Potomac flora had led him to give undue weight to certain resenlblances between thern, and, as it then seemed to me, he made identifications which entirely 

vitiated the a,ge determination. My conclusion was stated as follows: "I can see no valid 

reason for regarding this flora as other than Jurassic, or in any event as other than identical i 

with the flora frmn eastern Siberia, the Jurassic age of which is, so far as I know, universally 

accepted." I expressed a similar view in my paper "The Jurassic age of ·the 'Jurassic flora of 

Oregon,." 1 and still entertain it. 

The following is the con1plete list of speciea as given by n1e in the preliminary report 1nade 

to Collier,:! with the corresponding identifications of the present paper in brackets: 

'Cladophlebis huttoni (Dunk.) Font. [=C. huttoni]. 

. Dicksonin: n. sp.? [ =Coniopteris burejensis]. 

Dicksonia burejensis Zalessky r =Coniopteris burejensis]. 

Treniopteris parvula Heer [ =Pityophyllum nordenskioldi]. 

]~quisetum sp. [=E. collieri n. sp.]. ' 

Podozamites lanceolatus 1.-ttifolius (Schenk) Heer [ =P. I. eichwaldi]. 

Podozamites sp. [ =P. lanceolatus]. 

Baiera palmata Heer [=Zamites megaphyllus]. 

Phren.icopsis angustifolia Heer [ =P. angustifolia]. 

Phcenicopsis speciosa Heer [ =P. speciosa]. 

Pagiophyllum kurrii (Pomel) Schimp. [ =P. kurrii]. 

Stachyotaxus septentrionalis? (Ag.) Nath. [ =P. kurrii]. 

~1\txi tes su bzamoides? Moller [ =P. kurrii]. 

Ginkgo huttoni Font., n. var. [=G .. digitata]. 

This revised list of species in the Collier collection is as follows: 

Coniopteris hymenophylloides (Brongniart) Seward. 

Coniopteris hurejensis (Zalessky) Seward. 

Cladophlebis huttoni (Dunker) Font~ne. 

?Cladophlebis alata. Fontaine. 

Equisetum collieri n. sp. 

Poclozamites lanceolatus eichwaldi (S'chimper) Heer. 

Podozami.tes htnceolatus (Lindley and Hutton) Braun. 

Otozamites giga.nteus 'l'h'omas. 

Zamites megaphyllus (Phillips) Seward. 

Phrenicopsis speciosa Heer. 

Phrenicopsis angustifolia Heer. 

Elatides curvifolia (Dunker) Nathorst. 

Pagiophyllum kurrii (Pomel) Schimper. 

Pagiophyllum steenstrupi Bartholin? 

Pityophyllum nordenskioldi (Heer) Seward.· 

Fieldenia nordenskioldi Nathorst. 

Ginkgo digitata (Brongniart) Heer. 

AGE OF THE PLANT-BEARING BEDS. 

The bearing of these plants on the age of the beds in which they are found may now be 

considered. As already stated, the first material from the Cape Lisburne region was studied 

by Lesquereux, who regarded it as probably of Neocomian age. This n1aterial, together with 

1 Am. Jour. Sci., 4th ser., vol. 30, p. 50, 1910. 2 U. S, Geol. Survey.Bull. 278, p. 29, 1906. 
42 CONTRIBUTIONS TO GENERAL GEOLOGY, 1913. 

a small la.ter 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 Collier collection appears to have proved this assignment beyond reasonable question. 

Of the 17 species from the Cape Lisburne region noted in the present paper, the following 

al.so occur in Amurland, eastern Siberia: Ooniopteris burejensis, 0. hymenophylloides, Podozamites lanceolatus, P. l. eichwaldi, Phmnicopsis speciosa, P. angustijolia, Ginkgo digitata, and 

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

that portion of the Middle Jurassic (Brown Jura) known a.s the Bathonian, and so far as 

known to me, this assignment has not been disputed. Seward in his late paper says: ''The. 

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

In 1876 Heer 1 described a large number of Jurassic plants from the Government of 

Irkutsk, eastern Siberia, and in 1911 Seward and Thomas 2 reported on a small collection from 

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

nomenclature there appear to be in these Irkutsk collections the following species in common 

with those from Cape "Li.3burne: Ooniopteris burejensis?, Ginkgo digitata, Phmnicopsis speciosa, 

P. angustijolia, Podozamites lanceolatus, P. l. eichwaldi, and Elatides curvifolia. 

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

Bathonian or lowest Callovian age, near Kamenka, district of Izium, Government of Kharkow, was described by Thomas 3 in 1911. The following species fron1 Cape Lisburne are 

represented in this flora: Ooniopteris hymenophylloides, Cladophlebis huttoni, Ginkgo digitata, 

Elatides curvijolia, Otozamites giganteus, and Podozamites Zanceolatus. 

A small collection embracing 14 species from th~ western border of Mongolia, in Chinese 

Dzungaria, was described by Seward 4 in 1911. The :Mesozoic strata of thi.s region, according 

to Obrutschew, who collected the plants, reach the enormous. estin1ated thickness of 3,500 

meters, thus approaching the thickness recorded by Collier for the Cape Lisburne region: The 

following species are common to the two localities: Ooniopteris hymenophylloid~s, Ginkgo digitata, Phmnicopsis angustifolia, ,and Podozamites lanceolatus. On the basis of the plants the 

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

the world. Seward calls attention to the "remarkable resemblance between Rhretic and 

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

persisted from the Rhretic period to the middle or even to the latest stage of the Jurassic era." 

This resemblance will be alluded to later. 

Seward 5 has described a small flora from Caucasia and Turkestan, from beds of Middle 

Jurassic age or older, which includes the following species found also at Cape Lisburne: Ooniopteris hymenophylloides, Podozamites lanceolatus, Ginkgo digitata, and Phmnicopsis angustifolia. 

In 1876 Heer 6 described over 30 species of plants from the vicin1ty of Cape Boheman, 

Spitzbergen. The beds in which they were found were regarded by Heer as b~longing ·to the 

Brown Jura (Bathonian), and N athorst,7 who revised the flora in 1897, then confirmed this 

position, but later 8 he procured evidence which induced him to regard the age as near or 

above the Oxfordian-that is, in the Upper or White Jura. The species from Cape Boheman 

represented in the rocks of Cape Lisburne are Podozamites lanceolatus, P. l. eichwaldi, Ginkgo 

digitata, Phmnicopsis angustifolia, and Pityophyllum nordenskioldi. 

In the paper last cited Nathorst also enumerates anew the Upper Jurassic plants from 

Advent Bay, Spitzbergen, Fieldenia nordenskioldi and Elatides curvifolia being in common 

with Cape Lisburne; The flora of Franz Josef Land, regarded by N athorst as younger than 

1 Heer, Oswald, Flora fossilis arctica, vol. 4, pt. 2, pp. 28-86, 1876. 

2 Com. geol. Mem., new ser., pt. 73, 19ll. 

a Idem, pt. 71, 1911. 

f Idem, pt. 75, 1911. 

o Idem, pt. 38, 1907. . 

o Heer, Oswald, Flora fossilis arctica, vol. 4, pt. 1, pp. 26-471 1877. 

1 Nathorst, A. G., Kongl. Svenska Vetenskaps-Akad. Handl., vol. 30, p. 6, 1897. 

s Nathorst, A. G., Fos~dl plants· from Franz Josef Land: Norwegian North Polar Exped., vol. 1, No.3, 1900. 

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THE JURASSIC FLOR~ OF CAPE LISBURNE, ALASKA. 43 

that of Cape Bohmnan and Siberia, appears to have nothing in common with that of the Alaskan· locality. . 

The large and interesting flora. of the island of Bornholm, which was first described by 

Bartholin and later and In ore fully by Moller, 1 was regarded by the latter as of Rhrntic or 

Liassic age. It is, as Seward has pointed out, "no doubt. younger than· the Rhrntic floras of 

Scania, Tonkin, and Franconia, and the number of Lower Oolite species which it includes 

would seen1 to favor the view that its a.ffinities are rather with Jurassic than with Rhrntic floras 

of other regions." This statement is, at least ·to some extent, borne out by the following 

species fr01n Cape Lisburne which are found also in Bornholm: Podozamites lanceolatus; Ginkgo 

· digitata, Phmrnicopsis angustifolia, and Pagiophyllum kurrii. 

Turning now to the rich and well-exploited Jura8sic floras of England, we find Ooniopteris 

hymenozJhylloides, Ginkgo digitata, and Zamites megaphyllus, of the Great Oplite (Bathonian), 

in con1n1on with the Alaskan flora here discussed. Sin1ilar beds in Sutherland carry Ooniopteris 

hymenophyZloides, Ginkgo digitata, and Elatides curvifolia. 

The rich Jurassic flora fron1 Douglas County, Oreg., as worked up by Fontaine, 2 includes 

the following species which appear to be present also in the Cape Ljsburne region, though not 

all are listed here under the smne names: Ooniopteris hymenophylloides, Thyrsopte'ris murrayana, 

Cladophlebis vaccensis, Podozamites lanceolatus, P. l. latifolius, P. pulchellus, Ginkgo digitata, 

and Phamicopsis sp. 

Fr01n the composition and wide distribution of this flora as outlined above, the final 

conclusion is reached that the Corwin formation of the Cape Lisburne region is undoubtedly 

Jurassic in age, belonging either ir1 the upper part of the Middle Jurassic or Brown Jura, or 

the extreme lower portion of the Upper Jurassic or White Jura-that is to say, it is pi·obably 

not older t.hnn the Bathonian and certaiuly not younger than the Oxfordian. 

·DISTRIBUTION OF JURASSIC FLORAS. 

GEOGRAPHIC RANGE. I . 

At this point it way be of general interest briefly to review the character and geographic 

nwge of Jurassic floras, especially as developed in Arqtic and Antarctic regions. The wide 

areal distribution of l\1.iddle unci Upper Jurassic floras has long been one of the· marvels of 

plunt distribution. The living flora, of course, affords n~any individual exan1ples of.wide distribution, such as those found throughout the Tropics of both hemisphetes, and others, chiefly 

weeds, that have, la.rge]y through human agencies, spi·ead widely over ten1perate lands, but 

u.ltogether thPse plants form but an insignificarit part of the whole flora, whereas in Jurassic 

ti111e a huge percentnge· of the whole flora was practically world-wide in its range. 

In Alnska well north of the Arctic· Circle is found the interesting flora described in this· 

pnpe1·. Although only a few fossil species are at present known, to occur at Cape Lisburne, 

it is .rnore tlutn probn ble that the nun1ber would be greatly increased by careful exanunation, 

but the region is difficult. of access a.nd we n1ust possibly await the exploitation of its coal 

resources before adequate investigation of the flora will be made. 

'!'.he J'urassic flora has been found at a nu1nber of other localitie~ in Alaska, the farthest 

norLh being a point between ~cy Cape and Wainwright Inlet; about 180 n1iles northeast of 

C11pe Lisburne. Another locality is near Nikolai, in the Copper River region, wluch has 

afforded a single species of Sagenopteris that is closely related to a forn1 from the Lower Oolite 

of Italy and has also been found in· Oregon . and California. This species came from a bed 

now known as the ICennicott fonnation, 3 where it was.found in association with n1ar.ine invertebrates of Upper Jurassic age. · The iargest representation of Jurassic plants in Alaska, aside 

from th.at of Cape Lisburne, is found qn the north shore of Cook Inlet,. where seven or eight 

species wm·e obtained. These occur in the 11Enochkin forn1ation'.' of Stanton and l\1artin,4 in ·------------------- 1 Moller, Hjalmar, Kongl. Svenska Vetenskaps-Akad. Hamil., vol. 36, No. 6, 1903. 

2 U. S. Geol. Survey M:on. 48, pp. 47-145, Pls. VI-XXXVIII, 1905. 

a U. S. Geol. Survey Bull. 448, pp. 31-43, 1911. 

• Geol. Soc. America Bull., vol. 16, pp. 397 et seq., 1905. 

19205°-14-2 
44 CONTRIBUTIONS TO GENERAL GEOLOGY, 1913. 

intimate association with marine shells regarded by these authors as the· equivalent- of the 

Callovian of European standards, or the upper part of the Lower Oolite of English geologists. 

The last Alaskan locality to be mentioned is Herendeen Bay, which has yielded a single species 

of Pterophyllum. · . 

The. only other important North American localities are those in Oregon and California, 

which together have afforded l 01 forms. The collections from these localities are· especially 

rich in forms of Cladophlebis; Treniopteris, Sagenopteris, Nilsonia, Pterophyllum, Ctenis, 

Ctenophyllum, Podozamites, and Ginkgo. No less than 47 per cent of these species are found 

also in Jurassic beds in other parts of the world, notably in Alaska, eastern Siberia, and Yorkshire, England. 

The areas geographically nearest to the Alaskan localities are those of eastern Siberia. In 

1876 I-Ieer published his first paper on the flora of these areas, which included material from 

Kajamundung, Ust-Bali, the upper Amur River, and Bureja. This was supplemented in later 

years by the study of further ;material from the original localities as well as from Lena Delta, 

etc. The total number of species finally aggregated about 100, and many of them have since 

been identified in widely scattered parts of the world, the greatest number being common to 

the beds in Oregon and California and in Yorkshire, England. · 

As a complete enumeration of the Jurassic floras of the world is impossible for lack of space 

in the pre~ent connection, the following list of localities may be given as a partial indication 

_of their wide range: · 

United States: 

South Dakota. 

Wyoming. 

California. 

Oregon. 

Alaska: 

Cape Lisburne. 

Near W~inwright Inlet. 

Nikolai. 

Cook Inlet. 

Herendeen Bay. 

England: Yorks~Yire. 

Scotland: Sutl1erlan:d. 

France: Mammers. 

Germany: 

Franco-Swabian area. 

Northeastern area. 

Austria-Hungary: 

Steierdorf, Banat. 

Crojic,' Galicia. 

J<;r~kau. 

Italy. 

Switzerland. 

Portugal. 

. Sweden. 

Spitz bergen: 

Cape Boheman. 

Advent Bay. 

Green Harbor 

King Karls Land. 

Franz Josef Land. 

Greenland: 

Cape Stewart. 

East Coast. 

Siberia: 

Amurland. 

Irkutsk. 

Lena Delta. 

Chosen (Korea). 

Japan. 

Caucasia. 

Turkestan. 

India: 

Cutch. 

Jabalpm•. 

Chlna: 

Tyskyp-Tag. 

Border Rami Desert. 

Australia: : 

New Zealand. 

Graham Land: Hope Bay. 

The .flora of Graham Land·, whi~h has recently ,been carefully ,el~b9rated. by lialle,t is 

worthy of more .than· p~s·sing ·n.otic·e. ·.This flora comprises 61_ forms dispersed among the larger 

groups as follows:.-··Filicales _25, Cycadales 17, Coniferales 16, unknown 3. It is of interest to 

note that the Ginkgoales, which for:m an important and varied element in the northern henlisphere, are entirely absent £rom the Antarctic locality, as indeed they are from the Gondwanas 

of India, and th~t Podozamltes,· which ls abundant ~nd variable ln the _north, is absent from 

the Hope Bay collection and-.is represented only by doubtful fragments in the Indian localities. 

Of the 22 species from Graham Land that were previously known, 9 are common to the Lowm~ 

1 IIal_le, T. ,G., Mesozoic flora of Graham .Land: Wissensch. Ergebnisse der schwedischen Siidpolar-Expedition, 1901-1903, vol. 3, pt. 14, pp. 

1-123; Pis. I-IX, 19l3. . . . . 
THE .J-UHASSIC · F.LORA .OF_ CAPE LISBUR~E , __ ALASKA. 45 

Oolite of Yorkshire·, England, 8 to the Upper Gondwanas ·of India, and 5 to the Jurassic of 

Cnlifornia and Oregon. · In the nea.rest continent, South Ainerica, there a.re no flora.s of- a.ny 

importn.nce that can be considered contemporaneous with this Antarctic flora. 

"\iVith the foregoing outline of the distribution of Jurassic floras in inincl, we are perhaps in a 

position to draw certain tentative conclusions as to their probable avenues and means of dis-.· · 

persn,l and clinutt.ic requirements. The systematic groups with which we mainly have to deal 

are the Filicnles, Equisetales, Cycadales, Ginkgoales,· and Coniferales. 

MEANS OF DISPERSAL. 

The chief factors which are adduced to explain ·the distribution of living plants are animals, 

especially birds and 1nanunals; water, especially strean1s and ocean currents; air currents; and,. 

of course, human agencies. 

In considering the distribution of Jurassic plants we may at. once eliminate mamn1als,. 

which were in Jurassic tin1e on the threshold of their development, and birds, which were• 

represented by a single known· type (Archmopteryx) that at best must have ·enjoyed but. 

lilnited powers of flight. 'rhere rmuain, therefore, ·only air and water transportation to account. 

:for the distribution of Jurassic plants. None of the plants is believed to have possessed any 

marked mechanistn for wide and systmnatic dispersal. 

The :ferns of the Jurassic period are believed to have been homosporous, which·implies-~ 

the production of vast nu:n1bers of spores o~ relatively short-lived vitality. A considerable, 

number of living ferns having spores of this character are widely distributed on both. hemi-· 

spheres. The 1nale fern is an example; a single plant, -according to Bower, may produce in 

one season· 5,000,000 spores, which are particularly well adapted to wind dispersal. That. 

ferns may pass over at least- 25 1niles of open W!1ter is shown by Treub, who found that on the 

isln.ncl of l(n.:rakatau, which bad been completely wrecked and sterilized by a volcanic outburst,. 

within three years 12 species had already bec01ne reestablished. While the air currents may· 

have been c01npetent to acc01nplish this, the possibility of other agencies, such as transportation 

by birds, ocean currents, or n1an, should not be ignored. 

The ]~quisetales were not an i1nportant element. in the Jurassic flora, being n1ostly represerited. by :fragmentary 1naterial referred to Equisetun1 or Equisetites. Although many of the: 

.living species enjoy a wide distribution, little evidence is available as to their n1eans of dispersal. 

The Cycn.dalcs arc seed-bearing plants, the seeds being of small or 1ncdium size. In the· 

liv.ing species the seeds sink in fresh water .and presun1ably would do the same in salt water .. 

Tho .length of time they would retnin their vitality in salt water is problematical, though. 

probahly it would be very short. Their transportation for any great distance by water is open 

to ques~ion. 

The Ginkgoales are very distinctly a waning type; in fact, they have come almost to the 

\ 7 ttnishing point, for the single living -species. is not believed to exist in a purely wild state. 

The identification of the early forms now con1n1only referred to the Ginkgoales is founded 

mninly on the foliage organs, and their seeds m·e·not certainly known, but since the discovery 

of true Ginkgo in late Triassic or early Jurassic beds, m1d in practically its present form, the 

seeds have not infrequently been found. - These seeds, like those of the living species, are of 

large size. They have no special means for extended dispersal. 

In the living Coniferales there are certain n1inor devices for limited seed dispersal, such. 

a.s variously winged seeds, but nothing that is especially remarkable. The seeds of Jurassic 

Conifernles, so far as known, possessed no ·special devices for wider dissmnination than that. 

usually taking place on a land surface. 

AVENUES OF DISPERSAL. 

The data presented in the foregoing paragraphs regarding the n1eans for dispersal would' 

seem to indicate a practically continuous land conne·ction between the several localities eluting 

Jurassic time. With the possible exception of the ferns, whose spores might have been trans-
.. 

46 CONTRIBUTIONS TO GENERAL GEOLOGY, 1913. 

ported by air currents over very considerable distances of open water, none of the types 

appear to have posS'essed any mechanism or device by which they could have spread so widely . 

without a practically continuous ·land route. It is of course possible that masses of earth 

covered with living vegetation-floating islands, so called-may have been torn from the land 

l>y streams and carried intact for considerable distances into the sea, as similar "islands" are 

now transported by the Amazon and other rivers, but the distance over wl;tich such masses 

would be effective in colonization is relatively short. 

. The striking· similarity between the Jurassic floras of northwestern North America and 

eastern Siqeria shows that the land connection between these localities during ·Jurassic· ti1ne 

must 4ave been practically contii:mous. The known presence of Jurassic beds at I-Ierendeen 

Bay on the Aleutian Islands is at least a partial coP.:firmation of the presence of this land· 

bridge. If we may assume that the land adjacent to what is now Bering Sea was the centeror at least an i1nportant center-of distribution for the Jurassic floras, then, with communication established between the two continents,. the way was open for. a wide range over the 

northern hemisphere. . . . . 

The presence of a well-marked Jurassic .flora in the Antarctic. .region goes far toward 

justifying the presumption of a former land connection to that regio~, for the present distance 

is so great as ·to preclude· the r~asonable probability that the flora could have reached there 

otherwise. 

PROBABLE CLIMATIC CONDITIONS. 

With the abundant data now available certain tentative conclusions may perhaps be 

drawn as to the climatic conditions which existed during the life of. th~ Jurassic flora. There 

is no evidence that this flora was depauperate or pinched as the result of adverse cli1nate. 

On the COJ.?,trary, the presence of large and luxuriant ferns, many of them tree ferns, and cyc~ds, 

and of very abundant and large-sized leaves of Ginkgo, etc., especially in localities far north 

of the Arctic Circle, ~ffords ev.ery. evidence tliat ·the conditions of growth were !'avorable 

From the wide distribution of g~nera and species it appears that the conditions were also 

relatively uniform. In other words, there must. have been abundant or sufficient moisture 

and a ternperature that would permit the growth of such plants. ICnowledge of the probable 

moisture arid temperature requirements of a flora n,ow represented only by fossil1·emains n1ust 

be gained by a study of the nea~est relatecllivirig flora. On this basis it seen1s safe to assume 

. that the Jurassic flora indicates ·a moist, warm, possibly subt;ropical climate. · 

THE FJ...jORA. 

CoNIOPTERIS BUREJENsis (Zalessky) Seward. 

Plate V, figure 1. 

Coniopteris burejensis (Zalessky) Seward, Jurassic plants from Amurland: Com. geol. Mem., new ser., pt. 81, p. 22, 

Pl. I, figs. 1-5; Pl. III, figs. 18-21, 1912. 

Dicksonia burejensis Zalessky, Notes paleophytologiques; Com. geol. Bull.; vol. 22, p. 192, Pl. III, figs. -1-·J; Pl. IV, 

figs. 1-5, 1904; Knowlton, in Collier, U. S. Geol. Survey Bull. 278, p. 29, 1906. 

Dicksonia n. sp., Knowlton, in Collier, loc. cit. · 

Cladophlebis ;;accensis ':Varcl, Fontaine, in Ward, U.S. Geol. Survey Mon. 48, p. 157, Pl. XXXIX, figs. 7, 8, 1905. 

In 1904 Zalessky described . a fruiting fern from. Amurland under the name Dick sonia 

burej'ensis, at the same time calling attention to its resemblance to Dicksonia coria~ea Schenk/ 

from the Jurassi~ of China, D. concinna Heer, from Amurland, etc. In his recent work, cited 

above, Seward redescribed and refigured the Zalessky specimens, together with additional 

material recently procured, under the name Coniopteris burejensis, largely on the ground that 

the fossil is undoubtedly congeneric with Ooniopteris hymenophylloides. If it is to be held 

that Coniopteris is congeneric with Dicksonia, then the former is untenable, for it dates from 

1849, while. Dicksonia was founded in 1788. However, as there is some doubt as to their 

1 Schenk, A., Jurassische Pflanzen, in Richthofen's China, voj. 4, p. 254, Pl. LI, fig. 2; Pl. LII, figs. 5, 6, 1883. 

. ..,_ 
THE JURASSIC 'FLORA OF CAPE LISBURNE, ALASKA. 47 

generic identity it 1nay be well enough to retain the form under Coniopteris. It has usually 

been assun1ed ·that t4ese plants belong to. the family Cyatheacere, but of this .more will be said 

·later. · 

The salient features of Ooniopteris burejensis are described by Seward as follows: 

:Frond bipinnate or probably tripinnate; pinnre linear-lanceolate, attached to a comparatively slender rachis 

along tho margins of which the pinnre axes and the lamina of the basal pinnule on the lower side of the pinna are 

decurrent. The pinnulos may be oval and serrate, like those of C. hymenophylloides, or longer and narrower, the linear 

lamina being serrate, or more deeply dissected into smal~ oval segments; the latter form appears to be identical with 

that of some of the specimens described by Heer as Dicksonia gracilis and D. glehniana. In the larger exainples the 

rachis is broader; the more widely separated pinnre give a more open habit to the leaf, in marked contrast to the more: 

compact form. The venation is of the Sphenopteris type. 

In spite of Seward's elaborate explanation of the· diversity in form and appearance of the 

sterile fronds referred to 0 .. burejensis, .it is ·difficult to believe that· all are correctly referable 

to a single species: The lmig, narrow pinnre with linear serrate laminre (cf. figs. ·1s and 20 

of Sewn.rd's Pl. III) 1nay very well be the sterile portions of the form that bore the fruiting 

specin1en, but it would seem that the loi1ger, oval, slightly serrate pinnules such as are shown 

in his Plate III, figure 19, .are. too different to have come from the smne species. However, 

the collection n1ay have contained many specimens that were not figured and some of these 

n1ay bridge the apparent differences. 

The :fi_ne fruiting specimen from Cape Lisburne shown jn Plate V of the present paper 

is referred with n1uch certainty to 0. burejensis. It. is a frond of large size, being probably. 

between 30 and 40 centimeters in length and at least 20 centimeters broad. It is tripinnatified,. 

or quadripinnate. 1'he n1ain rachis, which is over 3. millimeters in diameter and slightly zigzag, 

was evidently very stiff. and rigid. ·The primary pinnre are rmnote, alternate,· at irregular 

distances, and spreading at the tips, giving the frond a very open, spreading effect. The rachis 

is relatively strong n,nd smnewhat angled. The secondary pinnre. are also alternate, sessile, 

lanceolate in general outline, and cut into nun1erous linear, deeply cut pinnules. The ·sori 

are tenninnl on slightly reduced laminre. 

The single ~·pecilnen referred by Fontaine 1 to- Cladophlebis vaccensis vVard, a species. first 

described f1;om the Jurassic of Oregon, is at best very obscure. It does not have the nervation 

ascribed to G. vaccensis, though in the shape of the pinnules there is not much difference. It is 

undoubtedly the san1e as the forn1 shown in Zalessky's Plate III, figures 1, 1a, and refigured 

by Sew1:"Lrd in his Plate III, figu1~e 19, and is to be referred to Goniopteris burejensis. 

CoNIOPTl<Jins HYl\1ENOPHYLLOIDES (Brongniart) Seward. 

Plate V, figure 2. 

Conio]Jteris hymeno]Jhylloides (Brongniart) Seward, Jurassic flora of the Yorkshire coast, p. 98, Pl. XVI, figs. 4-6; Pl. 

XVII, figs. a., G-8; Pl. XX, figs. 1, 2; Pl. XXI, figs. 1-3, 3a., "1, 4a, 1900; Fontaine, in.Ward, U. S. Geol. Survey Mon. 

48, p. 59, PI. VIII, figs. 1-3, 1905. 

S7Jhenop;te1'is hymenophylloides Broqgniart, Prodrome, pp. 51, 198 (nomen], 1828; Histoire des vegetaux fossiles, p. 189, 

Pl. LVT, figs. 4, 4b, 1829. 

Adiant'ites amurensis·Heer, :Flora fossilis arctica., vol. 4, pt. 2, p. 94, PI. XXI, figs. 6a., b; enlarged, figs. 6, c, d, 1876. 

'.l'his is m~e of the n1ost abundant and widely distributed of Ju~·assic plants, having been 

reported frmn the Antarctic, many localities· throughout the Arctic, Siberia, China, Japan, 

Ger:nlt"Lny, France, England, and Oregon, and now frmn Alaska. ·As n1ight ·be expected from 

the .number of students who have handled it, it has been reported under several generic names 

(Sphenopteris, Th):·sopteris, Dicksonia, Acliantites, etc.), but it all seen1s conspecific and is 

best included under the son1ewhn,~ noncornnlittal nmne Coniopteris. 

'.l'his species is repre~ented in the Cape Lisburne n1aterial by the single pinna figured, but 

fortunately this fragrnent is excellently preserved and there can be no doubt as to the correctness 

of its identification. It .is, for instance, not to be. distinguished frmn a specrmm~ from the 

J'urnssic of Yorkshire, England, figured by Smyard. 2 • 

1 Fontaine, W. M., U. S. Oeol. Survey Mon. 48, p. 157, Pl. XXXIX, figs. i, s, 1905. 

2 Soward, A. C., Jurassic flora of the Yorkshire coast, Pl. XVI, fig. 6, 1900. 
'48 CONTRIBUTIONS TO GENERAL GEOLOGY, 191.3, 

· ·The specimen ·from.Douglas County, Oreg., figured by Fontaine/ has probably been. cor-

:rectly determined but is· an indistinctly preserved fragment. The enlargements (figs. 2, 3) 

which purport to show the sori are, however, entirely incorrect, there being really no trace. 

·Of the fruiting condition. The slightly involute margins of the tips of the pinnules were evidently 

mistaken by the artist for immature sori. 

A comparison of the specimen frmn Cape Lisburne with Adiantites amurensis- from .Amurland 

.as figured by Heer z• shows them to be undoubtedly identical, and, as suggested by Seward, 3 

1,here is no doubt about referring the Amurla)ld specimen to Coniopteris hymenophylloides.' 

CLADOPHLEBIS HUTTONI (Dunker) Fontaine. 

· Plate VI, figure 3. 

Cladophlebis huttoni (Dunker) Fontaine, in Ward, U. S. Geol. Survey Mon. 48, p. 161, Pis-. XI;;I-XLIII,. 1905: 

Knowlton, in Collier, U.S. Geol. Survey Bull. 278, p. 29,.1906. 

This species-'-one of the most abundant ferns in the Cape Lisburne region-has been so 

fully described and illustr~ted by Fontaine in the publication above cited that it is unneces-

:sary again to go over the ground. The 011e or two examples fron1 the Collier collection are 

:here figured simply for the purpose of showing that ·they are undoubtedly .the same as the 

:specimens identified by Fontaine as Cladophlebis huttoni (Dunker). From the general shape 

:and disposition of the pinnre and pinnules, as well as the character of the netvation, there can 

Jbe no doubt, it would seem, as to the correctness of referring these fronds to the genus Clado-

·phlebis, but whether they are to be positively identified with Dunker's Neuropteris huttoni, 4. 

from the Wealden of I-Ianover, is or may be quite a different thing.· Fontaine is very positive 

·On this point, saying: "This fern [Neuropteris huttoni] has an uncommon aspect, and it resemtbles so closely the ferns from Ala"ska that there can be no doubt that they belong to the san1e 

·species," but of this I an1 not so sure. It appears that only one fragment .of the Hanoverian 

plant was found, this being a portion of a very strong· rachis about 5.5 centimeters long and 

·.tw,o more or less perfect pinnre. Dunker's figure was copied by Schimper, 5 who changed the 

name ·to Alethopteris huttoni, and the origina.l specin1en was later studied and again figured 

by Schenk.6 Schenk's figure differs somewhat fron1 the original one, showing. apparently tha.t 

the specimen is really somewhat less perfect than would appear fron1 Dunker's figure. It 

·:seems not unlikely that this I-Ianoverian plant should be referred to Cladophlebis denticulat.a 

{Brongniart); at least it seems strikingly sin1ilar to SOfl?.e that have been so referred-such, 

for .instance, as one figured by Seward 7 fron1 the Jurassic of Yorkshire. 

The figure of the type specimen of Dunker's plant shows the pinnre to be, as .in Cladophlebis denticulata, sessile but not decurrent on the main rachis, whereas in the Alaskan fronds 

the pinnre are distinctly decurrent and, as Fontaine ·pointed out, there is an occasional pinnule 

on the main· rachis between the insertions of the pinnre. It was undoubtedly a very large fern. 

One specimen in the Dumars collection-shown in Plate XLi of Font~ine's report-is 32 centimeters in length, and as it lacks both base ancl apex was probably twice as long when perfect. 

'The main rachis in this example was n1ore than 5 millimeters thick. The secondary pi.J.1nro 

have a tendency to be opposite on the rachis, though in the upper portion they may become 

:somewhat alternate.· They arise at an ang~e of about 45° and curve outwa.rd slightly so ns 

to become approximately at right angles to the rachis. In the lower and middle portions of 

the frond 'the pinnre are cut deeply ii1to ovate-lanceolate, slightly falcate divisions or pinnules, 

these being mainly entire, though some of them are provided with a few low teeth·; the pinnules are for the most part rather acute. The lower pmnules of the lower ulti1nate pinnre 

I Fontaine, W. M., U.S. Geol. Survey Mon. 48, Pl. VIII, fig. 1, 1905. 

2 iioer, Oswald, Flora fossilis arctica, vol. 4, pt. 2, Pl. XXI, figs. 6a-d, 18i6. 

a Seward, A. C., Com. geol. Mem., new ser., pt. 81, p. 19, 1912. 

4 Dunker, W. B. R. H., Monographie der norddeutschen Wealdenbildnng, p. 9, Pl. VIII, fig. 1, 1846 .. 

5 Schimper, W. P., Traite de paleontologie vegetate, vol. 1, p. 5i0, Atlas, Pl. XXXI, fig. 10, 1869. 

a Schenk, A., Palreontographica, vol. 19, p. 21i, Pl. XXIX [VIII], figs. 1, 1a, 18il. 

1 Seward, A. C., Jurassic flora of the Yorkshire coast, Pl. XIV, fig. 1, 1900. 
~I THE .JURAS~IC FLOR4- OF CAPE LISBURNE, ALASKA. 49 

are leo,st united. Toward the ends of the ultjn1ate pinnrn and il1 the tern1inal portions of the 

cmnpound ends they are n1ore and n1ore united and pass into lq bes and teeth, the size being 

at the smne tune din1inished. · 

'J~he nervation is desc1'ibecl by Fonta:ll1e as follows: 

'.l'he midnerve goes off very obliquely and at about two-thirds the distance to the end 'of the pinnule splits up 

into branches, after 1J1e fashion of Cladophlebis, so that the plant is a well-marked type of that genus and in the absence 

of fructification must be placed in it. The lateral nerves, i.n proportion .to the size of the pinnules, are quite slender. 

They are immersed i~1 the leaf substance and are not conspicuous. They go ofi very obliquely and are forked one or 

more times. ~i'he lowest are' the n'lost copiously branched. The forking is notably low down on the nerve, so that 

the branches are unusually long. On 1J10 lower side of the base of the pinnules one or more lateral nerves go off from 

the mn..in rachis. In the more separated pinnules the lower lateral nerves curve away from the midnerve, but in the 

lobed nnd dentate forms the inte~ior basal ones often curve inward toward it. 

On taking everything into account it seen1s probable that this fern should receive a new 

name, but it is so robust and abundant a forn1 that it probably had a wide distribution. in 

Arctic lands, not being ·confined to the vicinity of Cape Lisburne, and rather than give it n. 

ntune ·which might possibly prove to be a synoqy1n of son1e form lmown fron1 less complete 

mn.terinl, I mn pennitting it to ren1a:ll1 under the name given by ·FontailH~. It is very much 

to be doubted, however, that this fern is identical with the Neuropteris huttoni of Dunker. 

~CLADOPHLEBIS ALATA Fontaine. 

Plate V, figures 3, 4; Plate VI, figure 4. 

?CladOJJhlebis alata Fontaine, in '\lard, U. S. Geol. Survey Mon. 48, p. 158, Pl. XXXIX, figs. 9-11; Pl. XL, 1905. 

Onych,:aJJS'is psilotoides (Stokes and Webb) Ward, idem, p. 155, Pl. XXXIX, figs. 3-6. 

PecOJJter·is dent·iculata Heer, Lesquereux, U. S. Nat. Mus. Proc., vol. 11, p. 32, 1888. · 

It is with n1u.ch hesitation that this species is pennitted to ren1ain under the designn.tion 

given it by Fontaine in his review of the flora of Cape Lisburne, especially in view of the fact 

th11t Berry 1 has 1nerged the original C. alata with C. browniana (Dunker) Seward, a con1n1on 

fonn in the Patuxent and Arundel formations of Maryland and Virgini~L. That it is identical 

with the Pototnac for1ns is extren1ely doubtful, but tha~ it is the same as the nun1erous speciJnens fr01n Cape Lisburne that were so designated by Fontaine there can of course be no question. At fust it was thought tht1t this forn1 represented the sterile foliage of Coniopteris burejen,sis, and this supposition may ultunately be verified. For instance, the portion of the sterile 

pinna shown in Plate V, figure 4, is certainly strikll1gly si1nilar to the upper pinna on the right-

. lumcl side of the figure• of C. bur~jensis shown in Plate V. · They are of about the same sjze, 

have the linear pinnules set at the san1e strict angle, and are cut nearly to the same degree. 

It is not to be denied that the sterile portions of. the specin1ens here called Cladophlebis 

alata have a rather striking resemblance to Onychiopsis psilotoides (or mantelli, as it is more 

frequently called). Thus, the ye.ry large lower pinna shown in Plate V, figure 3, is similar 

in' gen.eral appearance to the figure given by Seward 2 of a specimen. of 0. mantelli from the 

English Wealden. Both these specin1ens show well the strict habit of the plants, and both 

lack the finer details of the outlines of the ultimate divisions. In the Alaskan specimen the 

pinnules are s01newhat larger, but otherwise the difference is apparently not great. It was, 

of course, this general resmnblance which induced Fontaine 3 to identify certain specimens 

in the earlier collections 11s Onychiopsis psilotoides, yet it is ·impossible to distinguish these 

frOJn a huge nutnber here referred to Cladophlebis alata. For instance, the pinna shown in 

Plate V, figure 3, is not to be separated fr01n figure 5 of Fontaine's plate above cited. 

O.tl the whole it soen1s best, pending the finding of additional material, to leave this form 

under the name given it by Fontaine, with the frank confession that such disposition is recognized as neither adequate nor fmal. 

1 Berry, E. W., Maryland Goo!. S~ey, Lower Cretac&ous, p. 243,·1912. 

2 Seward, A. C., Fossil plants of U1e Wealden, pt. 1, Pl. II, fig. 1, 1894. 

~Fontaine, W. M.., U. S. Goo!. Survey Mon. 48, p. 155, Pl. XXXIX, figs. 3-6, 1905. 
50 CONTRIBUTIDNS TO QENERAL GEOLOGY, 19la. 

EQUISETUM COLLIER! n. sp. 

Plate V, figure 5. 

Stem very little flattened or distorted, about· 6 or 7 millimeters in diameter and about 

5.5 centimeters long between the nodes, slightly swollen in the nodal region, and with about 

eight relatively verystrong longitudinal ribs and corresponding channels; sheath very·short, 

appressed; teeth apparently .of the same number as the ridges,· about 12 millimeters in length, 

slender and sharply acuminate at apex, each lying closely appressed in a groove; tubercles, 

or enlarged subterranean portions, present·at the lower node. 

This species is based on the only example noted" in the Collier eollections and has been named 

for the collector. As may be seeri, it has been little flattened or otherwise distorted and may 

be viewed nearly in its entirety. It is ehiefly remarkable for the very prominent ribs and. ~orresponding channels, and the short sheath with. the loJ?.g, slender acuminate teeth ·closely appressed 

in the depressions. · 

I have very little doubt t~at this .ls the same as the form from Cape Boheman, Spitzbergen, 

described by Heer 1 under the name Equisetum · rugulosum: though the. present form i::; better 

preserved and admits of a fuller description of the essential characters. The size and the promi.-

nent ribs are evidently similar in both, though the Spitzbergen specimen is not swollen in the 

nodal region, and of course the character of the teeth can not be made out. · Rather than n1ake · 

a doubtful identification, .however, I have placed the Alaska specimen under a different nan1e. 

This sp~cies is also similar to the specimen of Equisetum burejense from Amurland shown 

in one of the figures given by Heer.2 This figure shows a ·portion of a stem with parts of two 

nodes and an attached "·tuber," as well as several scars, whence apparent.ly other "tubers" 

have been broken. The figure of. E. collieri shows the presence of' a·" tuber" of similar size and 

appearance, at least so far as can be made out, at the lower node. The· size of the sten1 is sinrilar 

in the two forms, though E. bur_ejense is not swollen in the nodal region nor are the longitudinal 

ridges so prominent·. · 

Seward,3 in commenting on Equisetum burejense, s·ays: "These incomplete specimens may 

be tubers of Equisetit~s, but they are hardly. worthy of a specific name." This attitude of 

mind i~ dealing with obscure or biologically uncertain forms is not the right orie, in my opinion, 

for if a plant is sufficiently well characterized to be used as a stratigraphic !nark its usefulness 

is increased by giving it a definite name that can be employed for reference, whether it is l,:>iologically allocated or not. 

Nathorst,4 who reviewed Heer'~ Cape Boheman material, reduced'not only his Equisetum 

rugulosurf!> but also E. bunburyanum Heer and Phytotheca lateralis ~ · Heer to Equisetites sp., 

remarking that they are too poorly preserved and doubtful to be maintained. The fine transverse lines on. Equisetu'm rugulosum spoken of by Heer are, .according to N athorst, only checks 

in the carbonaceous covering. Be this as it may, there does not appear to be any doubt as ~o 

t_b.e correctness of referring the present Alaska form to Equisetum. · 

0TOZAMITES GIGANTEUS Thomas. 

Plate VI, figure 2. 

Otozamites giganteus Thoma.s, Jurassic flora of Karnenka: Com. geol. Mem., new ser., pt. 71, p .. 84, Pl. VI, figs. 1, 2, 

1911. . 

The single example figured is the only specimen of this species that has been found. It 

consists ·of a.portion of the rachis about 4 centimeters in length and the basal portions of three 

leaflets, only one of which, however, is anywhere near perfect. This most perfect leaflet is 13 

millimeters wide, and is preserved for a length of about 4.5 centimeters and was. presumably 

1 Heer, Oswald, Flora fossilis arctica, vol. 4, pt. 1, p. 32, Pl. VI, fig. 19, 1876 . 

. 2 Idem, pt. 2, p. 99, Pl. XXII, fig. 8, 1876. ' 

a Seward, A. C., Jurassic plants from·Amurland; Com. geol. Mem., new ser., pt. 81, p. 20, 1912. 4 Nathor.st, A. G., Zqr mesozoischen Flora Spitzbergens: Kong!, Svenska Vetenskaps-Akad. I:Iandl., vol. 30, p. 12, 1897. 

,_ 
THE JU}JASSIC l!"'LORA Ol!"' CAPE LISBURNE, ALASKA. 51 

some 7 or 8 centin1eters in length when liVing. The base .is plainly heart-shaped, with the 

upper side slightly the longer and apparently a little overlapping the rachis; the point of attachInent is a.pproxilnately in the center of the leaflet. The margins· of the leaflet are cmnpletely 

presel'vecl only near the base, but so far as can be made out little narrowilig is apparent. The 

nervntio.n all arises at. the point of attachment and thence radiates out with occasional forking 

to t:tcconunodt1te the enlarged area I~eached. 

The type locality for Otozamites giganteus is Kamenk3., in the district of Izium, in beds of 

Bnthoninn age (=upper part of :Middle Jurassic or Brown Jura), and until the present record 

the species had not been found elsewhere. 

ZAMITE~ l\fEGAPHYLLUS (Phillips) Seward. 

Plate VII, figure 1. 

Zmnites megaphylltts (Phillips) 80\vard, Jurassic flora, pt. 2, Pl'. X, figs. 4, 5; Pl. XII, figs. :1:, 3-5, 1904. 

Palmozmnia megaphylla Phillips, Geology of Oxford, p. 169, Diag. XXX, -fig. 6, .1871. 

!rites a.la.skana Lesquereux, U. S. Nat. Mus. Proc., vol. 10, p. 36, 1887. 

Baiera J>almata Heer, Lesquereux, idem, vol. 11, p. 31, Pl. XVI, figs. 4, 5, 1888 . 

.Nage·iopsislongifolia Fontaine, in Ward, U.S. Geol. Survey Mon. 48, p. 171, PI. XLV, figs. 1-5, 1905. 

Poaozmnites grandijol1:·us Ji'ontaine?, idem, p. 167, Pl. XLIV, fig. 1. · 

Leaflets coriaceous in textuTe, long, narrow, strap-shaped, slightly falcate, fltbruptly rounded 

at base, narrowed fron1 01~ below the middle to a long, slender~y acu1ninate apex; 1nargin 

pei·fectly entire; attachn1ent unknown but probably sessile by the narrowed base; :J?.erves dis-· 

tinct, parallel, not forking unless at base (which has not been clearly seen), 20 or 25 in nun1ber, 

each separated by about 10 thin, very delicate intertnediat'e veins. 

T'his species is represented by nearly twenty exatnples, none of which !s absolutely complete, as .all lack the extren1e base showing the point of attachn1ent. The character of the 

extrmne tip, however, is w'ell shown in sevetal speci1nens. The 1naximum len.gth observed js 

about 18 cCJ1titneters and the width 2.5 to nearly 3 c.entitneters. At least ·bvo of the specimens 

show thnt the base is becmning rounded to the point of attach1nent, but l)nfortunately none is 

quite clear at this place. The character of the n~rves, both the .larger and the fine intermediate 

ones, is plainly discernible in n1ost of the specin1ens; they are fully described ahove. 

It was at fu·st 1ny intention to describe this as a new species of Zamites, but on further 

co:nsider!1tion I f0und it itnpossible to distinguish the forn1 frmn Zamites 1r1:egaphyllus (Phillips), · 

as described and figured by Seward 1 fron1 the Great Oolite (Bathonian) of Stonesfield, England. 

Although Seward states that the English Inaterial consists almost entirely of detached leaflets, 

he was enabled to give the following diagnosis: 

Frond pinnate, pinnro attached to the rachis at a wide angle, reaching a length of more than 30 centimeters and 

a breadth of over 3 cc:mtimeters; linear in form, attached by a slightly contracted concave basal surface, which is 

somewlmt thickened; the lamina tapers gradually to an elongated acuminate apex, frequently falcate near the tip. 

Veins numet·ous and parallel, convergin~ slightly toward the base and apex of the pinnre. 

'I'his diagnosis, it will be observed, agrees absolutely With that drawn frmn the Alaska 

specimens. In the largest exa1nple figured by Sewarcl,2 which was 4 cent'inieters wide, the 

"lamina is tqwersecl by nun1erous parallel veins between which, as shown .in the drawing, 

occur finer longitudinal lines." In this particular, therefore, the .speci1nens frmn Cape Lisburne 

agree with the English species and apparently there can be no doubt as to their being correctly 

referred to it. · 

There has been 1nuch uncertainty as to the· generic reference for these fme leaflets. The 

first extunples of this form were obtained at the Corwin 1nine, in .the Cape Lisburne region, 

about 1885, by :Henry D. Woolfe. These were· studied. by. Lesquereux, who ·nan1ecl then1 

bites alaslcan(t on account of their presu1ned rese1nblance to leaves of the living Iris. l-Ie 

described them as follows.: "Leaves thickish, linear-lanceolate, tubulose at apex, narrowed to 

the base, falcate, equinerved; Ine4ian nerve obsolete; the lateral broad, equal.'' l-Ie also adds 

that the ''nerves are about 1 n1illimeter in width [apart], not very. prominent, equal, not 

t ~owo.rd, A. C., Jurassic flora, pt. 2, p. 111, 1904. s Idem., Pl. X, fig. 4. 
52 CONTRIBUTIONS TO .GENERAL GEOLOGY, 1913. 

separated ·by intermediate veinlets, very distinct." I have examined these speci1nens, which 

are preserved in the United States National l\1useunl, and fu1d then1 indistinguishable from the 

Collier specin1ens, except in size. The specin1ens of "!rites alaslcana," with additional examples 

collec~ed at the sa1ne locality by II. D. ·Dun1ars in 1890, were studied hy Fontaine and 

referred to Nageiopsis longifolia Fontaine, a very abundant form in the Patuxent fonnation of 

Virginia and Maryland. It has long been n1y opinion, and in this I anl. supported by E. "\iV.· 

Berry/ that these specimens from Cape Lisburne lu1.ve absolutely nothing to do with N ageiopsis 

nor of course with !rites. They have been con1pared carefully with the type and typical Jnaterial of Nageiopsis longifolia Fontaine, ~md they are not the san1e. It is b.elieved that they are 

not eve~ congeneric.2 

I mn also referring to Zamites megaphyllus the specin1ens that Lesquereux 3 referred to 

Baiera palmata I-Ieer and that Fontaine later referred with question to Podozamites grandifolius 

Fontaine. Both these authors fell into the error: of regarding thes~ leaves bottom side upthat is, as n1ay be seen on referring to Lesquereux's figure 4, the part figured as the base is in 

reality the apex. · Fontaine,4 in speaking of. these· speci1nens, expressed doubt as to their 

affmity but finally referred then1 to his Podozainites grandifolius, which is now placed under 

Otenopsis latifolia (Fontaine) Berry,S a rather -rare species of the· Patuxent fonnation of Virginia. 

Although these leaflets are if anything even larger than the Collier specimens here figured_, 

they do not differ otherwise, at least so far as can be made out fron1 their somewhat fragn1entary 

condition. · Pn<ENICOPSIS SPECIOSA I-Ieer. 

Plate VIII, figures 2-4. 

Phamicopsis speciosa Heer, Flora fossilis arctica, vol. 4, pt. 2, p. H2, Pl. XIX, figs. 1, 2; Pl. XXX, figs. 1-6, 1876. 

There are several examples in the Collier collections that clearly belong to Phcenic~psis 

speciosa as described and figured by I-Ieer fron1 Amurland. Three of these have been figured, 

the one shown in Plate VIII, figure 2, being the most perfect. Another (Pl. VIII, fig. 3) is 

a detached leaflet or segment 11 centimeters in length and nearly 1 centimeter in width, which 

is indistinguishable from the specin1en show~1 in !-leer's Plate XXX, figure 3. Apparently this 

very characteristic species has not previously been recorded from North America. 

Pn<ENICOPsrs ANGUSTIFOLIA I-Ieer. 

Phmnicopsis ang1tstijolia· Heer, Flora fossilis arctica, vol. 4, pt. 2, pp. 51; 113, Pl. I, fig .. ld; Pl. II, fig. 3h; 1876·. 

The Coll~er collection contains several fragments that· appear certainly to belong to Phcenicopsis angustifolia. Whether this ~pecies is really distinct or is refera?le to P. speciosa, as 

Seward 6 suggests, n1ust be left to the future to detenp.ine. The present speclinens are to be 

identifted with P. angustifolia but throw no light on the question of their identity with P. SJ?eciosa._ 

PonoZAl\UTES LANCEOLATUS (Lindley and I-Iutton) Fr. Braun. 

Podoza-mites lanceolatus (Lindiey and Hutton) Fr. Braun (non Emmons), Verzeichniss der .in der Kreis-NaturalienSammlung zu Bayreuth befincllichen Petrefacten, p. 100, 1840; Heer, Flora fossilis arctica, vol. 4, pt. 1, p. 35, 

Pl. VII, figs. 1-7, 1876; idem, pt. 2, p. 106, Pl. XXIII, figs.lc, 4a-c; Pl. XXVI, figs. 2-:10; Pl. XXVII, figs. 1-8,1876. 

The typical form of this variable type js represented by only a few fragments of rather 

large leaves that are too poor to figure. 

· t 1\{aryland Geol. Survey, Lower Cretaceous, p. 385, 1911. 

2 Since the above was written Hamshaw 'I'ho~as has published a short paper.(Some new a~d rare Jurassic plants from Yorkshire: Cambridge 

Philos. Soc. Proc., vol. 17, pp. 25&-262, Pls. VI, VII, 1913) in which he has described anew type of ginkgodianleaf under the name Eretmophyllum .• 

In discussing the relationship of this new form 'l'ho~as suggests the possibility that these specimens, referred by Fontaine to Nageiopsis longifolia, 

may really l;le referable to his Eretmophyllum. Continuing, he says: "F.oritaine's figure 5 might possibly be an Eretmophyllum leaf figured 

upside do,wn, and the shape of the other fragments, thin distant veins almost parallel but sometimes forking, presents some points of similarity." 

A comparison of the specimens studied by Fontaine, as well as·the Collier specimens here figured, shows that this suggestion is not without weight. 

'l'his may account for the fact that the leaves or leaflets are always isolated, and further they may have been improperly oriented. However, 

until further proof is forthcoming, it seems as well to leave them under Zamites. 

a Lesquereux, Leo, U.S. Nat. Mus. Proc., vol. 11, Pl. XVI, figs. 4, 5, p. 31, 1888. 

• Fontaine, W. M., U.S. Geol. Survey Mon. 48, p. 167, 1905. 

5 Berry, E. \V., Maryland Geol..Survey, Lower Cretaceous, p. 349, 1911. 

a Seward, A. C., Jurassic plants from Amurland; Com. geol. Mem., new ser., pt. 81, p. 21,1912. 
THE J"UHASSIC FLORA OF CAPE LISB1!RNE, ALASKA. . 53 

PonozAMITEs LANCEOLATus l!:IcnwALDr ·cs~himper) I-Ieer. 

Plate V, figure G; Plate VI, figme 5, part. 

Podozmnites lanc'eolat'l.ts eickwaldi (Schimper) Heer, .l~lora fossilis a.rctica, vol. 4, pt. 2, p. 109, Pl. XXIII, fig. 4; Pl. 

XXVI, figs. 2, 3, 9; Pl. XXVII, :figs. 1, 5c, 1876; ~athorst, Zur mesozoischen Flora. Spitzbergens: Kongl. 

Svenskn. Vetenskaps-Akad. HandL, vol. 30, p. 13, Pl. I, fig. 5, 1897. 

Podoza.m.itcs eickwaldi Schimper, Traite de pa.h~ontologie vegeta.le, vol. 2, p. 160, 1870; IIeer, Flora. fossilis arctica. 

vo1. 4, pt. l, p. 3G, Pl. VI, fig. 22c; Pl. VII, :fig. 7c; Pl. VIII, figs. 1-4, 1876 . 

.Podozmnites lci:nceolat'l.ts lat1f'oli'l.ts (Schenk) Heer, KnowJton, in Collier, U. S. Geol. Survey Bull. 278, p. 29. ] 90G. 

This fonn is very ·abundant and excellently well preserved in the Collier collections, and 

I-Ieer also speaks of i.t as being an 'abundant forin in the sandstones at Cape Bohetnan, Spitzbergen.. At :first I-Ieer described it with fuil specific rank, but later he inclined to regard it as 

1nerely a variety of the onulipresent ·P. lanceolatus, and this is the view taken by Nathorst, 

who restudied }leer's specimens together with tuuch additional h1aterial. Nathorst states that 

three for.ms of P. lanceolatus are present at Cape Boheman-P. lanceolatus genuinus, P. l. eich-

'I.Va.lcli, and P. l. ovalis. It is quite possible that a large series might show that these fonns so 

intergrade as to n1ake i.t unsn.tisfacto1'y to attmnpt to draw any sharp lines between thmn, but 

in the present collection they appear very distinct. For stratigraphic purposes the variety 

eichwctldi is· certainly 'vell 1narked, a fact which is of interest in the present connection as tend-· 

ing to connect the Cape Lisburne r~gion with other undoubted Jurassic localities. 

ELAT~DES cuR\rrFOI .. A (Dunker) N ~tthorst. 

Plate VIII, figure l. 

.Elrtt·ides curvijolia (Dunker) Na.ilwrst, Zur mesozoischen Flora Spitzbergens: Kongl. Svenslm Vetenskaps-Aka.d. Hand[ 

vol. 30, p. 35, Pl. I, figs. 25-27; Pl. II, figs. 3-6; Pl. IV, figs. 1-18; Pl. VI, figs. 6-8, 1897. 

Lycopodites CU'l'11'ijolins Dunker, Monogmphie der norddeutschen \Vea.ldenbildung, p. 20, Pl. vn, Jig. !), l84G. 

The single fragu~.entary exmnple figured is all that was noted of this species. 

PAGIOPHYLLUl\l KUiuur. (Pon1el) Schi1nper.· 

Plate VI, figure l. 

Pagiophyll'l.t7n k'!.trrii (Pomel) Schimper, Traite de paleontologi_e veget~le, vol. 2, j). 250, 1872; Moller, Bornholms fossila 

Flora, Gynmospermer: Kongl. Svenska Vetenskaps-Akad. Handl., vo1..36, p. 31, Pl. V, figs. 10...:12, 1903 . 

. Armwaria 1>eregrina p. p., Kurr, Beitrtige zur fossilen Flora der Juraformation Wiirttembergs, p. 9, Pl. I, fig .. 1, 1846. 

jJroreauia kuhrii Pomel, :Materia.ux pour 13ervir ala. flore fossile_ Jurassique de la France, p. 21, 1849. 

Thi.s species, described originally from the Jurassic of Wurttemberg, was found by :Moller 

at Bornholm in beds regarded as either Rhretic or Liassic. Whether }.1oller has been correct 

in determining the Bornhohn plants as identical with Pagiophyllum kurrii need not be discussed 

at this time, but it is certain th.at the specimens so figured and named by hii:n are not to b.e 

distinguished frmn the Cape Lisburne example- here figured. For instance, }.1oller's Plate V, 

·figure 12, shows a short branchlet with broad, rather obtuse leaves that is certainly the san1e 

as the specimen frotn Cape Lisburne. 

On the same piece of matri..'\: and lying very close to the branchlet from the Collier collection· 

is the apicn,l portion of another branchlet which may or may not represent a very immature 

cone. It is not well preserved and hence can not be made out with certainty. ·Just below the 

"cone" are two or three leaves of the same size and appearance as those 01~ the adjacent. 

brn.nchlet; below these the lea~es becmne crowded and apparently ·nan~ower and !?horter. 

It is, on the whole, probable that this is merely a growing tip in which the' leaves are not fully 

.developed.· 
54· CONTRIBUTIONS TO GENERAL GEOLOGY, 1913. 

pAGIOPHYLLUM STEENSTRUPI Bartholin~ 

Pagiophyllum steenstrupi Bartholin, Nogle i den bornholmske Juraformation forekommencle Planteforsteninger, p. 101, 

Pl. V, figs. 6-8; Pl. VI, figs. 1, 2, 4, 1894; Moller, Bornhol:rn;; fossila Flora, Gymnospermer: Kongl. Svenska Vetenskaps-Akacl. Harrell., vol. 36, p. 33, Pl. VI, figs. 1-3, 1903. 

The Cape Lisburne material contains two minut·e fragments that. appear to be the same . 

as the tips of branchlets such as are shown. in Plate VI, figure 3, of Moller's paper, cited above, 

but they are so small and uncertain as to make their identification more or less q_uestionable. . 

T~ese specimens also suggest Stachyotaxus septentrionalis (Ag.) N athorst, as figured by 

· l\tloller/ but there is ·not enough preserved to identify them certainly with that species. 

· PITYOPHYLLUM NORDENSKI0LDI (Heer) Seward. 

Pityophyllum nordenskioldi (Heer) Seward, Jurassic plants from Amurlancl: Com .. geol. ~fern., new ser., pt. 81, ·p. 30, 

Pl. II, fig.·17; Pl. III, fig. 22, 1912. . . 

Pinus nordenskioldi Heer, Flora fossilis arctica, vol. 4, pt. 1, p. 45, Pl. IX, figs. 1-6, 1876; idem, pt. 2, pp. 76, 117, 

Pl. IV, fig. 8c; Pl. XX, fig. 4, a, b; Pl. XXVII,. fig. 9a; Pl. XXVIII, fig. 4, 1876. 

This form is represented in the present material by several small fragments which are about 

3 millimeters in width and2 or 3 centimeters in length, evidently from the midd~e portion of the 

leaves. They have a single very strong median rib and show distinctly the peculiar transverse 

wrinkling sq well known in leaves o(this type. One fragment app.ears to show the presence 

of the longitudinal groove in the middle of the lamina that is regarded by N athorst as so characteristic of this species, though the others in close proxin1ity to it Clo not. It is probable, 

as.Nathorst has suggested, that the transverse wrinkling is in the. main a phenomenon of desiccation, though it was doubtless more or less connected with some structural peculiarity. . 

As Seward 2 has very well saic~, it is extremely difficult, if not impossible, satisfactorily to 

distinguish between many· of the Rhretic and Jurassic leaves that have been described from time 

to time under the name Pityophyllum. Thus I can see no marked distinction between what is 

here called P. nordenskioldi and. P .. staratschini (Heer) Nathorst,3 from Advent :Say, Spitzbergen. It also agrees closely with Taxi{es cf. gr{Lmineus (Heer) as figured by N athorst 4 from 

Franz Josef Land. Seward 5 has suggested that the leaves from the Jurassic of Oregon referred 

by Fontaine 6 to Nilsonia. parvula· (Tf£niop{eris:parvula Heer) are to be regarded as belonging 

to PityophyJlum, b.ut this can hardly be so, .for they are much larger than any usually referred to 

Pityophyllum, and moreover they have a lateral nervation exactly as figured by Heer under 

Tf£niopteris parvula. . · 

FIELDENIA NO~DENSKIOLDI N athorst. 

Plate VII, figure 2. 

Fieldenia nordenskioldi. N athorst, .Zur mesozoischen Flora Spitzbergens: Kongl. Svenska ·vetenskaps-Akad. Han ell., 

· vol. 30, p. 56,· Pl. III,. figs. 16-27, 189~. 

In the material from Cape Lisburne I·find several more or less well preserved leaves that 

I am unable to distinguish ·from N athorst's species, which con1es fron1 the Upper Jurassic of 

Advent Bay, Spitzbergen. The example. figured is nearly perfect except that the nervation 

is rather indistinct, though careful scrutiny discloses the presence of abont eight thin, parallel 

nerves. The point of the leaf is obtuse and rounded, the bt\sal portion is narrowed to the point 

of attachment, and on the whole this leaf is absolutely indistinguishable from that shown in 

figure 17 of N athorst's Plate III. 

As N athorst has pointed out, it is difficult, if not impossible, to distinguish between the 

present species and what Heer 7 has called Podozamites ensiformis and P. cuspiformis from., 

the Irkutsk, eastern Siberia. 

1 Op. cit., Pl. V, fig. 7. 

2 Seward, A. C., Jurassic plants from Amurland: Com. geol. Mem., new ser., pt. 81, p. 30, 1912. 

a Nathorst, A. G., Zur mesozoischen Flora Spitzbergens: Kongl. Svenska Vetenskaps-Akad. Handl., vol. 30, p. 68, Pl. V, figs. 32-36, 1897. 

• Nathorst, A. G., Fossil plants from Franz Josef Land: Norwegian North Polar Exped., vol. 1, No.3, Pl. II, figs. 20-23, 1900. 

~ Sew&rd, A. C., op. cit., p. 20. 

6 Fontaine, W. M., U.S. Geol. Survey Mon. 48, Pl. XVII, figs. 1-7, 1905. 

1 Heer, Oswald, Flora fossilis arctica, vol. 4, pt. 2, Pl. IV, figs. 8-10, 11, 12, 187G. 
THE JURASSIC FLORA OF CAPE LISBURNE, ALASKA. 

GrNKGO. DIGIT ATA (Brongniart) Heer.' 

Plate VI, figure 5, part; Plate VII, figures 3-5. 

Ginkgo digitata (Brongniart) Heer, Flora fossilis arctica, vol. 4, pt. 1, p. 40, Pl. X, figs. 1, 5a, b, 6', 1876. 

Ginkr1o h'lttloni (Sternberg) Heer, ~j'ontaine, in Ward, U. S. Geol. Survey Mon. 48, p. 170, 1905. 

Gi·nkrJo h-ttttoni m.agnijolia? Fontaine, idem, p. 170, Pl. X.LIV, figs. 7, 8 .. 

Ginkgo ht'l.tlt·inen;is Heer, Lesquereux, U. S. Nat. Mus. Proc., vol. 11, p. 31, Pl. XVI, fig. 6, 1888. 

55 

:Leaves of Ginkgo are abundant in the Cape Lisburne· collections, and it was un"<;loubtedly 

a conspicuous element in this flora, as indeed it 1~ust have been in all the northern Jurassic 

and early Cretaceous floras. In the Oregon collections, for instance, the genus is represented 

litern.lly by hundreds. of specimens, and it was equally abundant throughout eastern Siberia. 

This genus has been very nuiCh overburdened, for· in dealing with such an · abunda1ice 

of specimens and n1ultiplicity of fonns one 1nust needs 1nake either many "species" to acconlmoct'ate this diversity, or only one or two, and in view of the known. variatio.n exhibited by 

the single li\7 ing species, the latter plan seems pi·eferable. As a consequence, ail the Alaska 

specimens 1u·e here considered as referable to the ·extrmnely variable Ginkgo digitata. · 

· The first Ginkgo leaf known fr01n Cape Lisburne-namely, that fotind in Woolfe's collection-was .identified by· :Lesquereux as G. multinervis Hem!, a species described· fr01n the 

Cenomanian beds of Atane; Greenland. The same specin1i:m was later referred by Foptaine 

to G. h'l.tttoni (Sternberg) I-Ieer, but while the segrnents are cut nearly to the base, it does not 

diffe1· essentially fr01n 1nany referred to G. digita,ta. 

The two rather :fragrnentary leaves :froin the Dumars collection Fontaine referred with 

a question to his G. huttoni magn~foli(L/ narned froni the Jurassic of Douglas County, Oreg. 

Tho -vt1lidity of this variety ,will not be discussed at this time; and it is sufficient to say that 

· tho two specimens from Cape :Lisburne are here referred to G. digitata. 

t .Fontaine,\':. M., l'. S. Geol. Surve)· Mon .. 4S, p. 124, Pl. XXXI, figs. 4-8; Pl. XXXII, ftgs. 1, 2, 1905. 

•' 

PLATE V. · 

57 
PLATE V. 

FIGURE 1. Ooniopteris ·burejensis (Zalessky) Seward. 

2. Ooniopteris hymenophylloides (Brongniart) Seward . 

.' 3, 4. ? (J(adophlebis alata Eontaine. · · 

5. Equisetum collieri n. sp. 

6. Podozamites.Zanceolatus eichwaldi CHeer) Seward. 

58 
U. S. GEOLOG ICAL SURVEY PROFESSIONAL PAPER 85 PLATE V 

5 

JURASSIC FLORA OF CAPE LISBURNE, ALASKA. 
PLATE VI. 

59 
PLATE \TI. 

FIGURE 1. Pagiophyllum kurrii (Pomel) Schiro per. 

2. Otozamites giganteus Thomas. 

3. Cladophlebis huttoni (Dunker) Fontaine. 

4. ? Cladophlebis alata Fontaine. 

5. Ginkgo digitata Heer and Podozamites lanceol(~tus eichrwaldi (Heer) Seward. 

60 
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 85 PLATE VI 

3 5 

JURASSIC FLORA OF CAPE LI SB U RN E, ALASKA. 
PLATE VII. 

-··-- --___ -----==----=---__ -_ - __ . ---------- -- ----- -·=-=-=-=-==-~======--:-:-:::===========-~======= I 

61 
PLATE VII. 

FIGURE 1.. Zamites megaphyllus (Phillips) Seward. 

2. Fielden·ia nordenskioldi N athorst. 

3-5. Ginkgo digitata Heer. 

62 
U.S. GEOLOGICAL SURVEY 

2 

PROFESSIONAL PAPER 85 PLATE VII 

5 

JURASSIC FLORA OF CAPE LI SB URNE, ALASKA. 

3 

4 
PLATE VIII. 

63 
PLATE Vlll. 

FIGURE 1. Elatides curvifolia (Dunker) N athorst. 

2-4. Phmnicopsis speciosa ~eer. 

64 

.0 
U. S. GEOLOG ICAL SURVEY PROFESSION A L PAPER 85 PL ATE VIII 

2 

JURASSIC FLORA OF CAPE LISBURNE, ALASKA.