98 Dr Arber and Mr Goode, On some fossil 
evidence which is at all decisive. On the whole we are inclined ~ 
to regard it provisionally as a cupule, though we have not obtained _ 
any example of this organ either containing a seed or associated 
with seeds. On the other hand it is possible, of course, that it was 
a cup-shaped indusium enclosing sporangia, but. if this was so it 
differs greatly in size and in other respects from any Palzeozoic 
indusium which has so far been described. So far as it can be com- 
pared with Carboniferous cupules there is undoubtedly a certain 
resemblance. This is perhaps greatest in the direction of the 
fructification of Alcicornopteris Zeillert Vaftier*, from the Lower — 
Carboniferous rocks of France. The sterile frond of this species 
is recorded as having some resemblance to A. convoluta Kidst., a 
British Lower Carboniferous species in which the fertile fronds 
and organs are unknown. 
Vaffier’'s specimens are, unfortunately, not very well preserved. 
They show however a dichotomously branched axis terminating 
in organs which he calls indusia, but which nowadays. would no 
doubt be interpreted as cupules. Vaftier expressly compares 
these organs with Calymmatotheca Stangeri Sturt, now regarded 
as cupules. Here however the habit is different to the Devonian 
specimens, and the cupules are more deeply lobed. In neither the 
French nor the Austrian species do any seeds occur. Vaffier’s 
type, with six teeth, is no doubt specifically distinct from the 
specimens described here, although to us the resemblance is 
otherwise fairly close. 
There is also some similarity in habit to the British Coal 
Measure Lagenostoma Sinclairt Arb.{ in which however the cupule 
is less deeply divided, and to the German Devonian type figured 
but not described by Unger§ in 1856, which appear to show several 
cupules bearing seeds. If this is the right imterpretation of the 
latter specimen it is the oldest cupulate Pteridosperm known. 
While we incline to the cupule-interpretation of Xenotheca, it 
should be pointed out that somewhat similar structures have been 
described as spore-bearing. One of these is Codonotheca from the 
Coal Measures of the United States, described by Sellards|| and 
regarded by him as the male organ of a Newropteris. 
There is also a possible, but as it seems to us a much 
more remote comparison with the fructification attributed to 
* Vaffier, Etude Géol. et Pal. Carbon. Infér. Maconnais, p. 124, pl. vi. fig. 5; 
pl. vit. figs. fe la—1}, 1901. 
- + Stur, Culm Flora, Part 2, 1877, p. 151, text-fig. 27 on p. 158, pl. vit. 
figs. 5—7, 1877. See also more recent figures in Oliver, Biol. Centralb. Vol. xxy. 
p. 412, fig. 6, 1905. 
+ Arber, Proc. Roy. Soc. Vol. B 76, 1905, p. 251, pl. 1. fig. 11. 
§ Unger Denksch. K. Akad. Wissen. Wien (Math.-Nat. Cl.), Vol. x1. 1856, 
p. 184 (explanation to plates), pl. v1. fig. 25. 
| Sellards, Amer. Journ. Sct. Nel: xvi. 1903, p. 87; and New Phytol. Vol. vr, 
1907, p. 175. 
