Igit] JEFFREY—GEINITZIA GRACILLIMA 27 
Abietineae, particularly the older Abietineae, of the Pinus type. 
The discovery of an ancient pinelike conifer, Prepinus Jefirey, 
with generalized short shoots bearing many spirally arranged 
leaves, characterized by the possession of fibrovascular bundles 
with well developed centripetal wood of the archigymnospermous 
type, as well as the details of organization found in the leaves 
of certain Cordaites, appears to make it quite clear that we must 
look in the direction of the Abietineae, rather than in that of the 
Araucarineae, for the primitive representatives of the Coniferales. 
Summary . 
1. Sequoia gracillima, so-called, cannot be regarded as belonging 
to the living genus to which, on its superficial characters, it has 
been referred. 
2. It is an araucarian conifer, and in accordance with accepted 
principles of nomenclature should in future be referred to the 
genus Geinitzia. 
3. The structure of the cone axis in the so-called Sequoia gra- 
cillima (Geinilzia gracillima) vouches for the accuracy of the 
reference of detached cone scales of species of Geinitzia, and other 
araucarian conifers of similar type from the Lower Cretaceous, 
to araucarian affinities. 
4. The structure of the cone axis of Geinitzia gracillima, being 
less like the Araucarioxylon type than that found in the vegetative 
twigs of representatives of the genus from the Lower Cretaceous, 
urnished additional and independent evidence for the derivation 
of the araucarian stock from an ancestry essentially resembling the 
existing Abietineae. 
HARvarp UNIVERSITY 
EXPLANATION OF PLATE VIII 
Fic. 1.—A cone of Geinitzia gracillima, slightly reduced, viewed from 
opposite sides. 
Fic. 2.—Transverse section of the peduncle of the cone of G. gracillima. 
X 40. 
Fic. 3.—Longitudinal section through a higher region of the same cone. 
X40. 
Fic. 4.—Longitudinal section through the pith of the same. X8o. 
1G. 5.—Transverse section of the lower region of the cone axis. X 180. 
Fic. 6.—Longitudinal radial section of the wood of the cone. X 180. 
