398 
Slopes and Kershaw .— The Anatomy of 
Our new species, from the description given above, will be seen 
to agree with Prepinus of Jeffrey in all of the nine points except as regards 
the absence of centripetal xylem and the splitting of the bundle by a tongue 
of the inner thick-walled sheath. These two features, though of great 
specific importance, do not appear to us to weigh sufficiently against all the 
other points of agreement to exclude our species from the genus Prepinus. 
Further, only leaves are known in both cases, and among fossils, until the 
plants are known fairly completely, it is always a pity to multiply genera. 
For the present then we include our species in the genus Prepinus of 
Jeffrey, and as he has given no diagnosis of the genus, we offer one now. 
Prepinus, Jeffrey, 1908. 
Gymnospermic foliage resembling Pinus , but with many leaves in 
fascicle. In section the leaf has five straight sides ; two lateral resin-ducts ; 
a large zone of transfusion tissue round the bundle which may or may not 
be divided ; endodermis apparently absent; hypodermal sclerenchyma 
strands strongly marked. 
Only species :— Prepinus statenensis , Jeffrey, described Annals of 
Botany, 1908. 
Our species separates itself from Jeffrey’s through the absence of 
centripetal xylem, and the splitting of the bundle by the tongue of small 
thick-walled cells of the sheath. 
Prepinus japonicus, spec. nov. 
Leaf 1*5 mm. in diameter, central bundle split into two strands by the 
inner thick-walled sheath, no centripetal xylem recognizable. 
Locality :—Upper Cretaceous, Japan. Collected by M. C. Stopes. 
Type:—the figured slide has been presented to the British Museum, 
Department of Geology. 
Discussion. The characteristic shape of our leaf, and its similarity to 
those leaves of Prepinus for which the feature was discussed by Jeffrey (’ 08 , 
p. 208), seem sufficient ground for presuming that the leaves were in a multi- 
foliar fascicle as they were in Prepinus statenensis . Our leaf is so characteristic 
and so remarkably like Jeffrey’s in all important particulars save the 
absence of centripetal wood, that it seems to us to leave no doubt that it is 
truly of the same genus. It is only necessary to think of the living Cycads, 
in some species of which centripetal wood is found in the axis though it is 
absent from others, to realize that the point is hardly one of generic 
distinction. Our leaf comes from a geological horizon slightly more recent 
than the one which yielded the American specimens, and one might be 
tempted to present the view that the loss of the centripetal xylem was 
correlated with this. One might also point to the fact that the younger 
