DEScmrxioN of tiik sri:<;iEs. 127 



Thybsopteris crenata, sp. nov. 



Plat.- XXXIX, Figs. 1,2. 



Frond tripinnate, arborescent; pinnae and pinnules opposite; lower 

 penultimate pinn;u without j)innules or pinn;v near the insertion on the 

 niainrachis; leaf-substaiire of the pinnules thiek and leather\' ; piinia; of 

 the lower portion of the compound piniue parsing towards the sunnnit of 

 the compound pinn;e into crenately toothed and finally into entire pin- 

 nules; lower and basal pinnules crenately toothed, oblong to subquadrate 

 in form, separate to the nuich narrowed base; upper pinnules entire, ellip- 

 tical to subrhombic, slightly decurrent, united more and more in ascend- 

 ing; nerves of the crenately toothed pinnules composed of a midnerve 

 which dissolves into branches towards its sunniiit, sending off very 

 obliquely and alternately on each side nerve-bundles curving strongly 

 outwards to enter the teeth, and several times subdivided, in the upper 

 entire piimules composed of a midnerve sending off obliquel}^ and alter- 

 nately lateral branches curved outwards and forked one or more times, 

 or simple towards the tips of the pinnules; all lateral nerves strong. 



Locality: Fre(lericksl)urg ; rather rare. 



This fine plant seems to have no near affinity with any described 

 fossil. The rachises are strong, rounded, and prominent. 



Thyrsoptkris insignis, sp. nov. 



Pl:it,^ XXXIX, Fig. 4 ; Plato XL, Fig. 1 ; Plate XLI, Fig. 6; Plato XLII, Figs. 1,2,4; Plato XLIII, 



Figs. 1, 'i. 



Frond tripinnate, very large, arborescent ; leaf-substance of the pin- 

 nules thick and coriaceous ; rachises strongly winged, sometimes a little 

 flexuous ; pinnai of the first order very long and spreading ; ultimate 

 pinnae in the lower part of the frond very remote, subopposite to alter- 

 nate; pinnidcs quite variable, according to position on the frond and com- 

 pound pinnji?, and always rather remotely and very obliquely placed, 

 alternate to opposite, and decurrent ; in the lower part of the frond as in 

 PI. XXXIX, Fig 4, and PI. XL, Fig. 1, oblong-lanceolate to narrowdy 

 elliptical, acute, cut more or less deeply in the basal pinnules and very 

 obliquely into oblong or ovate acute lobes, those towanls the tips of the 



