ORGANIZATION OF .THE FOSSIL PLANTS OF THE COAL-~MEASURES. elo 
In view then of the fact that a renewed examination of Calamostachys Binneyana 
has tended to show that its anatomy is much more similar to that of Calamites than 
was formerly supposed, while another species of the genus has an exactly Calamitean 
structure, we think that the relation of our British species of Calamostachys to Cala- 
mites may well have been a close one. It is even possible that some of the stems which 
have been described under the general name of Calamuites, may have been those on 
which Calamostachys fructifications were borne.* Beyond this we cannot go, until 
evidence of continuity has been produced. We know for certain that the Palao- 
stachya type of strobilus was that of a Calamite, as is proved by the case of Calamites 
pedunculatus; it is possible that fructifications of the Calamostachys type may have 
belonged to other Calamitean stems. 
The solution of the problem must await further evidence. 
Ill. SPHENOPHYLLUM. 
The genus Sphenophyllum, BRonantaRt, is characterized externally by its compara- 
tively slender, articulated stems, bearing verticillate leaves, the number of which in 
each whorl is always some multiple of 8, as 6, 9, 12, 18, or even more. The leaves of 
successive verticils are superposed, not alternate. In the species on which the genus 
was founded (such as Sphenophyllum Schlotheimu, Bronen., and S. emarginatum, 
Bronen.), the sessile leaves are cuneate, widening rapidly from a narrow base, and 
having an entire or toothed anterior margin. From the form of such leaves as these 
the genus derived its name. In other species, however, the leaf is repeatedly divided 
in a dichotomous manner, into narrow segments, as in S. trichomatosum, Stur. In 
others, again, as in S. plurifoliatum, Wix1., one of the species which we are about to 
describe, the leaves are linear. 
The forms with deeply divided, or with linear leaves, cannot always be distinguished, 
by their external characters alone, from Asterophyllites, to which genus the species 
about to be described were originally referred.t Happily the anatomy of several 
undoubted species of Sphenophyllum is now well known,{ and agrees in all essentials 
with that of our own specimens, which have already been transferred to that genus.§ 
It is said that the finely divided foliage may occur on the lower portions of the 
same stems which bear cuneate leaves above. || This has been compared with the 
* Mr. T. Hick, in his paper above cited (see p. 905) arrives at substantially the same conclusion ; loc. 
cit., p. 291. 
+ Witiiamson, “ Organization,” Parts V. and IX. 
t Chiefly through the researches of M. Renaun, ‘Ann. Sci. Nat., Bot.,’ Sér. 5, vol. 18, 1873, and Sér. 6, 
vol, 4, 1877; also ‘Cours de Bot. Fossile,’ vols. 2 and 4. 
§ Witiramson, ‘ General, Morphological, and Histological Index,’ Part 2, p. 3, 1893. 
|| Conmans et Ktoxx,‘‘Monographie des Sphénophyllum d’Europe,” ‘Bull. de l’Acad. Roy. de Belgique,’ 
Sér. 2, vol. 18, 1864. 
MDCCCXCIV.—B. 6 B 
