11 
Sir Joseph Hooker. Of these Dr. Masters has been so 
good as to furnish the following brief explanation : — 
“ The arrangement of the genera in the following list 
differs in a few particulars from that adopted in Bentham 
and Hooker’s Genera Plantarum. The principal dif- 
ference consists in the maintenance of the Toxacece as a 
distinct order as originally proposed by Richard and 
followed by Endlicher, Lindley, and many other botanists. 
This arrangement permits of a more natural arrange- 
ment of the several taxaceous genera under two tribes, 
the Salisburinece comprising Ginkgo , Cephalotaxus, and 
Torreya, and the Taxinew including the two sub-tribes 
Taxece and Podocarpece. Prumnopitys, Philippi (with 
which Stachycarpus, Van Tieghem, is synonymous) is 
placed by Bentham and Hooker under Podocarpus, 
but the combination of morphological and histological 
characters point to the desirability of maintaining it as 
a separate genus. 
Among the Conifer w or Pinacece proper a few changes 
have been made from the grouping of Bentham and 
Hooker in accordance with the fuller knowledge of 
certain points of structure that is now available. 
Tetraclinis is proposed as a distinct genus, represented 
by the North African Callitris quadrivalvis, on the 
ground of its structure and geographical distribution. 
Widdringtonia is separated from Callitris for similar 
reasons. 
The sub-divisions of Cupressus and of Thuya have 
been bandied about between the tw r o genera. The genus 
Cupressus, as here understood, includes the Cypresses 
