1532 CORMOPHYTA. 



placed in this family by Dr Schenk ; but exclusive of this form we 

 have several genera allied to the existing Salisburia or Gingko-tree 

 of Japan and China, characterised by its fan-like leaves (fig. 1401). 



This genus had an almost world-wide 

 distribution in past times, being abun- 

 dantly represented from the Permian, 

 and if Saportea, from the Carboniferous 

 of Pennsylvania, be rightly included, ex- 

 tending as low as the preceding period. 

 It is very curious, as Sir J. W. Dawson 

 remarks, that this genus should now be 

 restricted to a single Asiatic species, al- 



Fig I4 oi.-Leaf of Gingko-tree thou g h {t will g row in temperate Europe 

 {Salisburia siberica)- from the an d America, without, however, usually 



Lower Cretaceous of Siberia. (Af- . . _.'_.. . 



ter Dawson.) producing fruit. In India it occurs in 



the Upper Gondwanas. Rhipidopsis, 

 from the Lower Jurassic of the Atlas and the Lower Gondwanas of 

 India, is an extinct genus with large leathery leaves usually divided 

 into five wedge-shaped segments, of which the middle one is the 

 largest. Other extinct genera are Dicranophyllum, from the Car- 

 boniferous of France, China, and Canada ; Trichopitys, from the 

 Jurassic of Europe ; the allied Czekanowskia, from the European 

 Rhsetic and Jurassic, the Jurassic of China, the Wealden of Portugal, 

 and the Upper Gondwanas of India ; and Fieldenia and Phomicopsis, 

 the former being from the Miocene of Spitzbergen, and the latter 

 from the Jurassic of Northern Europe and the Upper Gondwanas. 

 Many of these genera have the leaves divided into long slender 

 slips, but in the true Yews the leaves are simply acicular. The 

 existing genus Taxus, together with the closely allied or identical 

 Taxites, has a wide distribution, being well represented in the Ter- 

 tiaries and extending down through the Jurassic to the Rhsetic. 

 The allied Cephalotaxus, of China and Japan, in which the male 

 flowers are in clusters, and the seed is completely enveloped in 

 the fleshy capsule, is represented in the Tertiary and Cretaceous of 

 Greenland ; while another existing genus, Torreya, occurs in the 

 Tertiaries of Greenland and America. Finally, omitting some less 

 important types, the tropical genus Podocarpus occurs abundantly 

 throughout the Tertiaries of the greater part of the world. 



The genus Walchia (fig. 1402) may be taken as the representa- 

 tive of a group — the WalchiecE — which may perhaps serve to connect 

 the Yews with the Araucarias. In the type genus the secondary 

 branches or twigs are arranged alternately in two rows, and carry 

 spirals of angulated acicular leaves ; larger leaves covering the 

 primary branches in an imbricating manner. The fruit, according 

 to Dr Schenk, formed true cones, approximating to those of the 



