BY R. H. CAMBAGE. 385 



A. Schenk,* however, expresses some doubt, and exercises con- 

 siderable caution in criticising fossil specimens of Casuarina 

 described by Ettingshausen and Heer, and refers to fossils from 

 Bilin figured by Ettingshausen as of less value as proof of the 

 existence of the genus Casuarina in the European Tertiary, than 

 those described by Heer, which are nothing but the remains of 

 scarcely determinable twigs with opposite leaves. Heer's Sumatra 

 specimens Schenk considers are of much greater value, even 

 though the determination does not appear to him as absolutely 

 definite. 



From the Tertiary flora of New South Wales, Ettingshausenf 

 has described a species of Casuarina found near Emmaville and 

 named it C. Cookii. He describes the sheath-teeth as four 

 in number, which, it may be pointed out, corresponds with the 

 number found on C. torulosa Ait., a species common along the 

 north-eastern coast of New South Wales to-day, and extending 

 up along the eastern slopes of New England to within about 20 

 miles of where C. Cookii has been found. 



Whether the existence of the genus Casuarina in Europe or 

 America during Tertiary or Cretaceous time is ultimately proved 

 or not does not seriously afi'ect the question under discussion. 



That plants have persisted from late Tertiary time to the 

 present day is an acknowledged fact. Clement Reid, F.R.S.,| 

 writing on the origin of the British Flora, regards the Preglacial 

 period as latest Pliocene, and gives a list of plants including 57 

 genera and 75 species which are found fossil in the Preglacial 

 period and are also living plants, all but three being still in Great 

 Britain. 



Other instances could be quoted; and the same persistence 

 applies to the fauna as well. 



It must also be remembered that new fossil plants are often 

 necessarily described from very imperfect material, and although 



* Traits de Pal6ontoIogie. Par Karl A. Zittel. Partie ii. Pal^ophytologie. 

 A. Schenk, pp.396, 397. 



t Contributions to the Tertiary Flora of Australia. Ettingshausen, p.l07. 

 X The Origin of the British Flora, 1899, p.52, and pp. 171-179. 

 25 



