.in; Assic iLOKA OK norcrLAS corNTV. oinx;. (>] 



PI. \'lll. liir. 1. shows l)()tli coiiiiKM'pai'ts natural size. PI. \'ni, 

 I'ijr. '_'. ^i\('s, (Milarjieil, an u|)|)(m- hasal [)iiuiiil(\ and l''ig. '.i one from the 

 lerniinal poi'tion of tlie pinna. 



(Ipiuis TlIYKS()l''li:i;i> Kunl/.o." 



'riiVKsoriKHis MruHAVANA (Broiifiniart) Ileor.* 



IM. \ 111. Fi.<;s. III. 



ISIili. Picnptf ris M iirnn/diKi Broni^n.: 1 list . \'i'<;. Foss., p. .S.5S, pi. cxxvi, fi<;s. 1, 

 lA, 2-4, 4A, ry. r>A. 



"Mr. .Sewniil very iiatmally iIdiiIus ihc iicciMicnci' in a fossil state of a inonotvpir jjenus of ferns now 

 living, hut confined to the island of .hian Fernandez, and he thinks that the Cretaeeons species helong to 

 the extinct genus Onychiopsis of YoUohaina and the .Iura.ssic ones to lirongniart's C'oniopteris. In the Fif- 

 t(M'nth Annual Ueport of the United States (ieolosical Survey, I.S!)."), pp. ;j,S.'{ 381, 1 discussed this question, 

 referring to Thi/rsopteri': Miirraijuiia (Brongn.) lleer from the Oolite of Yorkshire, saying: 



" Hrongniarl had already pointed out the re.setnhlaiice of his I'ecopteris M iirmii<itia from the Oolite of 

 York.shire to this living genus, and had united this species with others iiUo a distinct genus, Coniopteris, to 

 which Saporta afterwards referre<l a numher of species from the .Jurassic of France. It is therefore very 

 probahle that the genus Thyrsopteris, which is now so nearly e.xtinct, was widely distributed over the northern 

 hemisphere in Jurassic time. We have in America no true .Jurassic flora thus far, hut should such u flora 

 hereafter come to light there can scarcely he any doubt that this genus will he found in it." 



This prediction .seems now to have been verified. In the .Nineteenth .Uuiual Keport, I'l. II. p. (i,")8 (foot- 

 note), the question of retaining the name was again raised. Seward and .Nalhorst regard all the forms as 

 belonging to extinct genera, but there is not conqjlete harmony among paleobotanisis on this point. l'otoni(5 

 in Kngler and Prantl's Xat. Pllanzenfamilien, Teil 1. .Vblh. I, Lief. l.SS, Leipzig, l!Si)',), p. 123, .says: "The 

 renuiins frotn the .lurassic of .Spilzbergen. of the Amoor country, and of England, especially those figured bv 

 Leekenby (l.S(j-l) and Ileer (l.S7()), including Thi/rsopliris Miirraijann (Brongn,) Heer, and T. jUaakiana 

 Heer, as well in their fertile as their sterile parts, so closely res(Mnhle the recent species T. elegant that it is 

 difficult to doubt the correctness of their reference to that genus." 



While, therefore, it is probable that all the fossil forms will ultinuitely be referred to extinct genera, 

 such genera must have do.sely resembled Thyi-sopteris and w<'re probably its early .Jurassic and Crelaei'ous 

 ancesloi's. The present isolated species must therefore be regarded as a last remiuint of a once widely dif- 

 fu.sed group of ferns, and belongs to the class of waning types, like (linlcgo hiUihii and the two surviving species 

 of Sequoia. The ease is therefore by no means an isolated one, and lieconu's highly interesting to the 

 student of plant development. — \j. F. W. 



''Although Mr. .Seward (.lur. Fl. Yorksh. Coast, p. KM)) refei-s Ileer's plant to Conuiplens hijiitenophjUoides , 

 Professor Fontaine sees reasons for keeping it distinct. After receiving Mr. Seward's book, 1 called his atten- 

 tion to the fact, and in a letter to ine, dated August 21, 1901, he says: 



"My idea wa.'5 that only those forms of Murrayana type ought to be united with Coniopteris that have 

 the proper fmctiiication, or are closely associated with it. There is no such fnietilication with the Oregon 

 forms. I think that the Murrayana type of fern is the sterile form of more than one .Jurassic species, and 

 It would be convenient to keep the name for any of that type who.se fructification is not known, and use it 

 as the name Cladophlebis is used. This was the rea.son why I retained the species." 



I give therefore in the synonymy only those references that are confined to this form as found in .lurassic 

 strata — i. e., to the original Yorkshire plant and to Ileer's specimens from l's(-I5alei in .Sil)eri». The Liassic 

 form Pecoplerix Pingelii Schouw, D'uksonia I'ingelii (Schouw ) Bartholin, from the island of Bornholm, although 

 thought by Brongniart to Ite perhaps the same, and generally so regarded by later authors, is onn'tted as of 

 earlier date involving change of name, and as still somewhat doubtful, but as it has always been as.sociated 

 with Pecoplerix Murrayana and not with Sphenopleris hymenophylloides, it is also omitted from the synonymy 

 of Coniopteris hymenophylloides. — L. F. W. 



