Bd. III: 14) 
THE MESOZOIC FLORA. 
83 
posed in a regular spiral, and such of dorsiventral habit with the leaves directed to two 
sides and thus affecting a pseudo-distichous arrangement. Forms of the former type 
are frequently referred to, for instance, Sequoia, Sphenolepidinm, Elatides, Pagiophyl- 
lum etc., of the latter to still more genera, such as Sequoia, Palissya, Stachyotaxus, 
Taxites etc. The best thing would seem to be, to create a provisional name for 
each of these two types. To begin with the latter one, there exists already a name 
which has largely been employed for forms of the kind in question, viz. Taxites 
Brgn. This genus is used for dorsiventral shoots more or less resembling those of 
Taxus; and the name might be extended to include all forms with a pseudo-distichous 
arrangement of the leaves. The name is unfortunate in so far as it seems to imply 
a close relationship with Taxus, whereas no such relationship may exist; and it is 
no doubt better to confine Taxites to receiving only such forms which there is 
some reason, from fructifications or otherwise, to regard as allied to the recent genus- 
There is one more reason against the extended use of Taxites, viz. that it seems to 
be inappropriate to have one name for the dorsiventral and another for radial shoots. 
There exist forms in which both types occur in one and the same specimen, even 
in one and the same branch. Such is the case in a well-known Rhætic species, 
Stachyotaxus septentrionalis (Agardh); such again in the plant described here as Ela- 
tocladus Jieterophylla n. sp. and in others. Elatocladus heterophylla is an example 
of a form for which it is impossible to find a suitable genus, unless Taxites is ex- 
tended in an undesirable manner; and it shows that, if a provisional genus is insti- 
tuted for sterile coniferous branches, the same will have to comprise both those with 
radial and those with dorsiventral shoots. It is for this purpose that the provisional 
generic name Elatocladus is here proposed. Elatocladus should contain sterile 
coniferous branches of the radial or the dorsiventral type, which do not 
show any characters that permit them to be included in one of the genera 
instituted for more peculiar forms. 
It may be argued that such specimens and species which are not well enough 
characterized to be included in any of the existing, better defined genera were better 
left unnamed. The fact is, however, that a fossil species may be rather well de- 
fined and easily recognizable, although it cannot be referred to any particular genus. 
And in the Coniferæ the generic determination of sterile fossil remains is, if anything, 
more difficult than in other groups, since many of the fossil genera are founded on 
the fructifications and the vegetative sy.stem does not vary conformably with the 
former. A great number of species referred to divers genera would no doubt better 
be kept under the provisional name here proposed. The existence of the genus 
Elatides need not cause any confusion. Since the structure of the cones has been 
made a character of that genus it had better be reserved for forms with fructifica- 
tions only. It may be feared that the genus Elatocladus will become in time an un- 
