48 CONXRIBUTIONS TO GENERAL GEOLOGY, 1913. 



Tho spocimon from Douglas County, Oreg., figured bv Foiitaim-,' hii-; probably been cor- 

 rectly dcternuiu'd but is an indistinctly preserved fragment. The enlargements (figs. 2, 3) 

 whicli purport to shovv^ the sori are, however, entirely incorrect, there being really no trace 

 of the fruiting condition. Tho slightly involute marguis of tlic tips of t lie piimules were evidently 

 mistaken by the artist for immature sori. 



A comparison of the specimen from Cape Lisburnc wit li Adiantites amurensis from iVmin-land 

 us figured by Heer - shows them to be imiKiubtodly identical, and, as suggested by vSeward.^ 

 there is uo doubt about referring the Amurland specimen to Ooniopteris JiymenophyUoidcs. 



Cladophlebis iuttoxi (nunker) Fontahic, 



Plate VI. figure 3. 



Cladophlebis huttoni (Dunker") Fontaine, in Ward, U. S. Geol. Survey Mod. 18. p. IGl. Pis. XLI-XLIII. 1R05; 

 Knowltoii. in Collier, U. S. Geol. Survey Bull. 278. p. 29, 190(!. 



This species — one of the most abundant ferns in the Cape Lisbunie region — has l)een so 

 fully described and illustrated by Fontaine m the publication above cited that it is unncces- 

 sarj^ again to go over the ground. The one or two examples from the Collier collection are 

 here figured simply for the purpose of showing that they are undoubtedly the same js the 

 s|)ecimens identified by Fontaine fis ChdopJdebis huttoni (Dunker). Fnun the general shape 

 and disposition of the j)iiina? and pumules, as well as the character of the nervation, there can 

 be no (loul)1, it would seem, as to the correctness of referring these fronds to the genus Clado- 

 phlebis, but wliether they are to be positively identified with Dunker's Neuropteris huttoni* 

 from the Wealden of Hanover, is or may be quite a difl'ereut thmg. Fontame is very positive 

 on this |)oint, sayhig: "This fern [Neuropteris huttoni] has an uncommon aspect, and it resem- 

 bles so closely the ferns from Alaska that there can be no doubt that they belong to the same 

 species," bxit of this 1 am 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 

 two more or less perfect pinna^. Dunker's figure was copied by Scliunjier.'' who changed the 

 name to Aldhopteris huttoni, and the origiital specmien was later studied and again figuretl 

 by Schenk." Scheak's figure differs somewhat from the origmal one, showing apparently that 

 the sjiecimen is really somewhat less ])erfect than would appear from Dunker's figiu'e. It 

 seems not unlikely that this Hanoverian plant should be referred to Cladophlihis dentieuJata 

 (Brongniart ) ; at least it seems strikingly similar to some that have been so referred — such, 

 for instance, as one figured by Seward ' from tlie Jurassic of Yorkshire. 



The figure of the ty|>e specunen of Dunker's ])lant shows the i)mmv to be, as m Clado- 

 phU'bis denticulata, sessile but not decuiTent on the mam rachis, whereas in the Alaskan fronds 

 the |)lnna' are distinctly decurrcnt and, as Fontaine ])ohited out, there is an occasional pmnule 

 on tlie main rachis between tiie insertions of the |)inna\ It was undoubtedly a very large fern. 

 One specunen in the Dumars collection — shown in Plate XLI of Fontaine's report — is 32 centi- 

 meters in length, and as it lacks both base and apex was probably twice as long when perfect. 

 The main rachis in this example was more than 5 miliinu^ers thick. The secondary |)inna> 

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

 somewhat alternate. They arise at an angle of about 45° and curve outward slightly so !?s 

 to l)ecome apjjroximatcly at right angles to the rachis. In the lower and middle ])ortions of 

 the frond the jjinna' are cut ileeply uito ovate-lanceolate, slightly falcate divisions or i)mnules. 

 these beutg mainly entu-e, though some of them are {jrov-ided with a few low teetii; the pin- 

 nules are for the most jmrt rather acute. The lower pumules of the lower ultimate puma' 



' Fontaine, W. M., I'. S. Geol. Survey Mon. 48, PI. VUI, ng. 1, 1905. 



5 Heer, Oswiild, Flora fo.ssilLs arctipa, vol. 4, pt. 2, PI. XXI, Dgs. Ba-d, 1X70. 



' Seward, A. C, Com. r&I. Mi'm., new ser., pt. si, p. I'.l, 1912. 



• Dunker, W. 1). K. II., Monograph io der norddeutsclicn Wealdenbildung, p. '.i, IM. VIII, fig. 1. lS4ii. 

 » Schimper, W. P., Trait(> de paleontologie viSgetale, vol. 1, p. 571), .\tlas, PI. XXXI, fig. 11), I,S6». 



• Sohenk, \., Palawntographica. vol. 19, p. 217, PI. X.XI.X |VI1I]. fig.s. 1, la, 1S71. 

 ' Seward, A. C, Jurassic Horn o( the Vorksliire coast, PI. .\IV. Tig. 1, 190(1. 



