156 On the Fossil Botany and Zoology of Australia. 



in long narrow leaves, having a more or less distinct midrib. 

 Inflorescence arranged in whorls near the extremity of certain 

 branches. 



I have only to add to the above characters, that the ridges of 

 the snlcated stems do not alternate at the joints in the regular 

 manner of Catamites, nor is there any trace of the peculiar tu- 

 bercles so generally seen in that genus (an additional proof, if 

 such were wanting, that Brongniart's original explanation of 

 those tubercles being connected with the vascular system of the 

 sheath is not the correct one, for here we have enormously de- 

 veloped sheaths and no tubercles). The verticillate whorls of 

 leaves, whenever I have seen them perfectly expanded, seemed 

 always elliptical as in Annularia, the leaves of two opposite points 

 of the circumference being considerably longer than the rest. 

 The genus is distinct from Annularia by the great development 

 of the sheath or connected base of the leaves, and by the branches 

 being inconstant, and when present, not being arranged in pairs 

 in the same plane. 



Phyllotheca australis (Br.). 



Sp. Char. Stem simple, smooth or slightly striated; sheaths 

 tight, shorter than the internodes, terminated by narrow 

 leaves, double the length of the sheaths, without distinct mid- 

 rib. (Condensed from Br.) 



Phyllotheca ramosa (M'Coy). PL XI. figs. 2 & 3. 



Sp. Char. Stem branched, smooth or slightly striated ; sheaths 

 half the length of the internodes; leaves thin, linear, flat, 

 twice to three times the length of the sheath, with a very fine 

 indistinct midrib. 



This beautiful plant has the branches weeping or hanging 

 downwards as in Casuarina, about half the diameter of the stem ; 

 they do not arise from every joint, but they do nearly ; I am 

 uncertain whether more than one spring from any one joint. 

 Most of the stems are perfectly smooth, being striated only at 

 the articulation (see PL XL fig. 3), while others have a delicate 

 lineation down the internodes ; the first I imagine to be stript of 

 their bark, and the latter to retain it ; and here again we have 

 another proof of the stronger affinity of our fossil to Casuarina 

 than to Equisetum, for I find by examining the living Casuarina 

 that the lineation of the surface goes no deeper than the bark, 

 while the elevated lines on the surface of Equisetum are only the 

 edges of strong septa going towards the central hollow, and the 

 flat spaces between those lines are only the superficial coverings 

 of tubular hollow spaces between the aforesaid septa, so that de- 



