62 



This interesting fern occurs in the Upper Mesozoic shales, 

 Dunally, where it was collected by the Rev. J. _ Button, 

 F.L.S. I have now great pleasure in associating its name 

 with its accomplished discoverer. 



TMnnfeldia polymorpha. (Nov. sp. Fig. 16.) 

 Frond bi-pinnate, dichotomous ; pinna: never dichotomous, 

 distant, opposite, sub-opposite or alternate,_ extremely 

 variable in form ; generally linear-lanceolate, linear-ovate, 

 and occasionally simply ovate ; bases contracted and some- 

 what auricled; margins variously and irregularly sinuous, 

 lobate, or simple ; in some the lobes are confined to the base 

 with narrow caudate extremities ; in others the lobes, shallow 

 and more or less irregular, are continuous throughout, and 

 in a few they are simple or rudimentary. Stalk thick, and 

 strongly grooved with an obscure nerve-like wing on either 

 margin ; each lobe has an independent set of fine branching 

 nerves similar in character and arrangement to those of 

 TMnnfeldia obtusifolia, Mihi., to which this strikingly variable 

 form has a close affinity in many respects. Were it not that 

 nearly every specimen "of this polymorphous fern is similarly 

 variable in the shales of Dunally, and the uniformly dicho- 

 tomous and regularly lobed form of T. obtusifolis is rarely to 

 be found there, I should hesitate in separating it from some 

 extreme forms of the latter, but in any case the distinctive 

 name now applied will serve a useful purpose for reference 

 independently of doubt as to its true organic alliance. 

 Length of the larger pinnae, about 2| inches; greatest 

 breadth towards base, 1-yV inch. 



Very common in Mesozoic shales near Dunally. Collected 

 by the Rev. J. Bufton, F.L.S. 



In my work on "The Geology of Tasmania" (Pt. xxyi„ 

 figs. 2, 6, and 20) I refer certain doubtful forms to Pecop- 

 teris caudata, Mihi. I am now inclined to refer them to the 

 above species, viz., T. polymorpha. 



Genus Cakdiopteeis. Schimper. 



The following definition of the above genus is taken from 

 M. B. Renault, Cours de Botanique Fossils (Fougeres, pp. 

 201-202):- 



" Frond pinee, rachis strie longitudmalement, cylmdrique, 

 pinnilles inserees perpendiculairment a la face superiurede ce 

 dernier, rapprochees, imbriquees, ovales, cordi formes, plus 

 pitetes a. la partie inferiure des pennes oil elles prennent une 

 forme circulaire ; toutes ont une forme smy etrique, et^ sont 

 inseprees parle milieu de leur base, coriaces, a bords infectus, 

 nervures egales naissant sur le rachis, plusieurs fois dicho- 

 tomes, et sepanouissant en eventail." 



Terrain Houiller. France. 



