of the Island of Sumatra, ^c. 405 



The appearance and nature of these productions would indicate a compara- 

 tively recent date to the event. 



The other large islands of the chain, Pulo Batu, Mantawi, and the Poggies, 

 are less known, but are probably not very dissimilar in structure to Pulo Nias : 

 they are not nearly so populous or so well cultivated; but the quantity of sago 

 and cocoa-nuts which they produce, sufficiently proves that they are not defi- 

 cient in fertility and natural resources. 



The islands on the eastern side of Sumatra are of two descriptions: those 

 which lie off the mouths of the Siak and Indragiri rivers, on the western side 

 of the Straits of Malacca, are merely alluvial flats ; while the islands of Banca, 

 Lingen, &c., may more properly be considered as belonging to the Malayan 

 chain, and as a continuation of the range which forms the peninsula of Ma- 

 lacca ; being similar to it in geological situation, and in their mineral products, 

 the most abundant and remarkable of which is tin.* 



* la the collection of rocks sent by Dr, Jack from Sumatra occurs a specimen, No, 19,345, of 

 soft white chalk, Creta scriptoria^ containing the fragment of an echinus. No mention of it is 

 made in the memoir, nor was any information contained in the label attached to it, except the 

 locality, Bencoolen, — Note by the Secretaries. 



