310 Mificellanea. 



whorl of distinct leaves "a sheath originating within them and 

 closely embracing the stem, to which it gives the appearance of 

 the barren shoots of ?in. Ecjuisetum,\\\i\). its whorls of slender branches 

 on the outside of a toothed sheath." Unger, in his ' Chloris 

 Protogsea,' referring both to Brongniart and Lindley and Hutton, 

 defines the plant as " Caulis simplex, rectus, articulatus vagina- 

 tusque. Folia verticillata linearia, enervia contracta v, expansa, 

 vaginas articiilorum strictas circumdantia." Mr. Morris, I believe 

 the latest writer on this plant, closely follows Brongniart in his 

 observations on its structure. 



I have now stated what I believe to be all the. published infor- 

 mation regarding this very interesting form ; and as it has not been 

 hitherto figured, and the published accounts are contradictory 

 among themselves, and none of them as T find strictly applicable 

 to the plant, it may be interesting to detail some of the observa- 

 tions I have been enabled to make on those specimens which have 

 come under my notice. 



I find in the whitish clay beds of Mulubimba a profusion of 

 plants having cylindrical jointed stems, the joints surrounded by 

 sheaths, and the free edge of each sheath terminating in a whorl 

 of long, linear leaves. Here we have all the essential characters 

 of Phi/llotheca, but beyond this there is no agreement with the 

 descriptions of those few botanists who have seen the plant. And 

 here I may be permitted to state, that, from the number of specimens 

 which I have examined with great care, there remains not a doubt on 

 my mind of the accuracy of M. Brongni art's view of the relation of the 

 whorls of leaves to the sheaths : I have traced them distinctly in 

 every instance as arising from the free edge of the sheath, and 

 lyiQg either straight, inclining obliquely outwards, or, as is most 

 commonly the case, completely reflexed, as I have represented in 

 the drawing PI. 11. fig. 2 : and their occurrence in this position 

 may have deceived INIessrs. Lindley and Hutton as to their real 

 connexion with the sheaths ; for when the long slender leaves are 

 completely reflexed and pressed in a reversed position against the 

 sheaths, broken specimens may easily have their inferior mistaken 

 for their superior extremities ; and if when in this position the 

 le^es be supposed to point upw^ards, they will really have the ap- 

 pearance of originating as an independent whorl of leaves outside 

 of the base of the sheath, as described in the ' Fossil Flora.' This 

 double arrangement would be so anomalous, that it is the more 

 important to "have the means of ascertaining the true relation of 

 those parts in accordance with Brongniart's original view. 



Brongniart describes the stem as smooth, and I find the specimens 

 before me apparently divisible into two groups, one having the 

 stem smooth, the other having it coarsely sulcated longitudinally, 

 as in Calamiies. All the botanists alluded to agree in describing 

 the stem of PhyUotheca australis as simple ; — all the sulcated stems 

 I have seen are simple, but a number of the smooth or slightlj'- 

 striated stems are distinctly branched, and in a manner quite dis- 

 tinct from Equisetum. In Eqidselum, if we view with most botanists 

 the sheaths as produced by the mere lateral union of the leaves, 

 and thus representing thefohage of other plants, we have the 

 extraordinary character of the branches arising, not as axillary buds 

 originating immediately above and within the base of the leaves, 



