1876.] Knowledge of the Fossil Flora in India. 349 



The most instructive specimen is that which I have figured (pi. xv, 

 fig. 3.), and it will be sufficient first to discuss this. 



It represents a thickish stem with a branch passing out of it. 



The stem appears at first sight to be of the same kind as Boyle's* 

 Yerteoraria indica, but our specimen has the " middle axis," if one can 

 so call it, broader. The whole stem shows the seemingly irregularly disposed 

 ' breakings' on both sides of the axis, but a closer inspection shows that 

 they are not so irregular. 



The only difficulty of observation is that the specimens are generally 

 very much crushed and have the outer coat destroyed, but the one under 

 discussion is better preserved than most others. 



The most important point about this specimen is that the whole smface 

 is regularly longitudinally ribbed, in the same manner as the fossil Galamites 

 or Fquisetum ; the ribs are rather broad, on the average about 2 mm., 

 and are separated by thick lines (or very thin ribs, as one may call them), 

 in the same way as is seen in some Galamites of the coal-measures. 



The ribs are in general continuous over a long portion of the stem, 

 but on some of the ' breakings' there are apparently interruptions of the 

 ribs ; the ribs ending regularly in the ' breaking' and the next ribs beginning 

 again independently. 



This reminds one very closely of the formation of an articiilation in a 

 Galamites or, indeed, in the Fquisetaceae in general, and I consider it as 

 representing an articulation. Our figure (pi. xv, fig. 3, a. a. a.) exhibits 

 these relations very well. 



So far they would agree completely with Galamites or Fquisetum, and 

 as regards the breadth of the ribs, mostly with some of the- Triassic forms. 



In these articulations the ribs do not alternate, as they generally do in 

 the carboniferous Galamites,f but are arranged as they almost always are in 

 the Triassic forms. 



Prom what I have said about this stem, I am quite certain that it 

 belongs to the Fquisetaceae or at least to some order in which the Galamites 

 must be placed ; which is shown by the ribbed surface and by the articula- 

 tions. But how to explain the ' breakings' of the stems ? They are not so 

 irregular as they seem to be at first sight. One thing is certain, that the 

 articulations which I have observed on our specimen are just in the ' break- 

 ings' ; perhaps this genus was very fragile at the articulations ; but Sir 

 Charles Bunbury's hypothesis could be right too. 



Yet another circumstance must be mentioned, which is of importance 

 and could partly explain the ' breakings'. Our specimen is also branched ; 



* 1. c. PI. 2. f. 1. 



f In the true Carboniferous I know of only one instance where the ribs do "not 

 alternate ; it is in the coal formation of Silesia. 



