186 Mr J. M. Macfarlane on Lepidopliloios. 



known as Ilalonia, \yliile the otlier in nowise differs from 

 a typical Lepidophloios stem, such as Schiraper and otliers 

 figure, except in size. I propose, for convenience sake, 

 though perhaps arbitrarily, to name Halonia the fertile, 

 and the latter the sterile, branches of Lepidophloios ; tlie 

 reason for this I will state hereafter. The latter, or so- 

 called sterile form, gives us no trace whatever of the 

 tubercles present in the fertile or Halonia form ; it is 

 possible, however, that such may appear at a more ad- 

 vanced age. Of this, however, we have no direct evidence. 

 They usually curve towards their extremities in a graceful 

 manner, describing at times a considerable arc of a circle, 

 and, as already mentioned, end rather abruptly. But 

 it is the so-called fertile part, which hitherto has been 

 designated Halonia, that is of particular interest to us. 

 Hitherto its relation to some other plant has been much 

 debated, some of the older authors regarding it as the root 

 of a Lepidodendroid plant (Wilde, "Geologist," 1863, p. 266). 

 More recently, and especially since its internal structure 

 has been ascertained, botanists have almost universally 

 looked upon it as being the axis of inflorescence of some 

 unknown genus, which, from the evidence I now advance, 

 appears undoubtedly to be Lepidophloios. If, then, Lepi- 

 dophloios does terminate thus, we should naturally wish to 

 ol)tain such an example as would sliow the transition from 

 it to that of Halonia by the gradual appearance of the 

 tubercles of the latter. This we have in the specimen 

 which I figure (Plate VII. fig. 1). Though we could have 

 wished that the primary axis had been preserved for us a 

 little further, enough remains to us to show that it was 

 devoid of the tubercular cicatrices till about an inch below 

 tlie point of bifurcation. There then appear on the exposed 

 surface of the stem two of the well-known tubercles, and 

 from that point upwards they are abundantly developed 

 in spiral order. 



As I previously stated, Principal Dawson has asserted 

 that some Halonias, which he figures, are the fruit axes 

 of Lepidophloios, without exactly stating his reasons for 

 supposing so. But a strong confirmation of the idea 

 which I have brought forward is to be found when we 

 turn to the internal anatomy. Tliis has been very elabor- 



