AN UNDESCRIBED FOSSIL VEIIT. .'91 



EXPLANATION OF THE PLATES OF TRIPLOSPORITE. 



T.V15. U (XXIII). 

 The liguics A, B, C, and D are of the natural size. 



Fig. A. A portion of the surfaee of the Strobilus, sliowing the licxagonal 

 areola?. 



Figs. B & C. Transverse seetions, exhibiting different appearances of the 

 liractese and sporangia. 



Fig. D. A vertical section of fig. A. 



The remaining figures, E, F, G and II, are all more or less magnified. 



Fig. E. A transverse section of the axis. 



Fig. F. A more highly magnified drawing of a portion of fig. E, to show the 

 arrangement and proportion of the vascular and cellular tissues. 



Fig. G. A horizontal section of a sporangium, made probably near its origin. 

 Fig. H. A portion of the outer wall of a sporangium or bractea. 



Tab. 35 (XXIV). 

 All the figures magnified. 



Fig. A. A vertical section of the axis, near, but not exactly in the centre, 

 sliowing the ramifications of the central cord of the axis going to the circum- 

 ference of the axis, and connected or supported by a loose cellular tissue at a a. 



Fig. B. A small portion of the axis, from which proceeds a bractea cut 

 vertically through its centre, showing its vascular cord, and bearing on its 

 lov/cr and horizontal half a vertical section of an adnate sporangium, of wiiich 

 the base is cellular, rising irregularly and vv^ithout spores, — probably a rare 

 occurrence. 



Fig. C. A small portion of the axis, to show the scalariform vessels with ""tTj 

 the slightly elongated surrounding cells. 



Fig. D. x\ similar portion, from the central axis of the bractea of fig. B. 



Fig. E. A similar portion, from the line of union between the bractea and 

 sporangium of fig. B. 



Fig. F. A small portion of a sporangium, sutTicicntly magm'ficd to show the 

 arrangement and composition of sporules. 



Fig. G. Several sporules, both in their compound and simple state, still more 

 highly magnified, with the minute granular matter which usually accompanies 

 them.' 



