23,1 Merrill: Distribution of Dipterocarpaceae 5 



explanation of the differences between the floras of eastern and 

 western Malaysia, and why the Philippines, lying to the north- 

 east of the Sunda Islands or western Malaysia and north and 

 northwest of eastern Malaysia, presents in its flora elements 

 from both of these two rather sharply differentiated regions of 

 the Malay Archipelago. 



We know comparatively little regarding the geological his- 

 tory of the Dipterocarpaceae. Brandis 2 states regarding the 

 five fossil species, described by Geyler from Borneo and Labuan 

 and placed in the genera Hopea and Dipterocarpus, that the 

 fragments show no characters which necessitate their being 

 placed in this family. He considers that the only fossil remains 

 described up to 1895 that could safely be classed here are those 

 described by Heer from the Tertiary deposits of Sumatra. Heer 

 describes two species of Dipterocarpus, one of which Brandis 

 thinks probably was a species of Shorea. Brandis concludes 

 that the fossil remains, therefore, throw no light upon the 

 development of this family. 



Comparatively little additional information regarding fossil 

 Dipterocarpaceae has become available since Brandis's work 

 was published. Holden 3 has described a fossil genus, Diptero- 

 carpoxylon, from the Tertiary of Burma, based on fossil wood 

 of a single species. Colani 4 has described another species of 

 this genus from Tertiary material supposed to have come from 

 Annam. 



Schuster 5 records Hopea fagifolia Miq. and Vatica lancifolia 

 Miq. from the Trinil beds in Java (Pleistocene). There seems 

 to be no question that Schuster's identification of these fossil 

 remains is correct. 



Edwards 5a has very recently described a new genus and 

 species, Dipterocarpophyllum gregoryi, from the Tertiary of 

 southeastern Burma which, however, is in all probability not 

 distinct from some living genus. He cites Crie's description of 



* Brandis, D., An enumeration of the Dipterocarpaceae, Journ. Linn. Soc. 

 Bot. 31 (1895) 4. 



8 Holden, R., Records Geol. Surv. India 17 (1916) 267. 

 4 Colani, M., Service Geol. Indochine Bull. 6 ' (1919) 2. 



• Schuster, S. J., Monographie der fossilen Flora der Pithecantropus- 

 Schichten (1911) 1-70, t. 1-27. Reprint from Abhandl. Kgl. Bay. Akad. 

 Wissensch. Math.-Phys. Klasse 25 (1911). 



s * Edwards, W. N., On some tertiary plants from South-East Burma, 

 Geol. Mag. 60 (1923) 159-164, t. 5. 



