274 EXPLORATION OF THE CAVES OF BORNEO. 



firms the opinion already expressed. It only remains to be added 

 that, with the exception of the bones mentioned in the enclosed 

 note by Mr. G. Brsiv, f.r.s., . which have been placed in the 

 Musenm of the Eoyal College of Surgeons, the whole of the 

 objects sent to England by Mr. Everett have been made over to 

 the British Museum. Accompanying this is Mr. Everett's first 

 quarterly report, together with his map and plans, so that they 

 may, if thought lit, be deposited in the archives of the Society, so 

 as to be available, if necessary, for future reference. 



REPORT OX THE EXPLORATION OF THE 

 BORXEAX CAVES in 1878-9. 



1. The Limestone Formation. 



2. The Caves and their Deposits. 



3. The Human Remains. 



4. Concluding Remarks. 



1. Limestone Formation. 



The caves of Sarawak are situated in a limestone formation 

 substantially identical with that of the Malay Peninsula, and 

 occupying a considerable area of the north-west and north-east 

 parts of the Island of Borneo. Its westernmost extension seems 

 to be represented by ths Ahup Hill on the frontier between 

 Sambas and Sarawak, whence it runs nearly uninterruptedly to 

 the upper waters of the Sadong River at Semabang. It reappears 

 in the Tatau River near Bintnln, and again comes to the surface 

 in the Niah, Baram, and Limbang rivers, in Brunei territory, and 

 it is known to be largely developed in northern Borneo. 



"Where the original structure ol the rock has not been ob- 

 literated by metamorphic action, it is found to be crowded with 

 organic remains (eucrinites, &c), but as these have never been 

 examined by palaeontologists, it is impossible to fix with any 

 approach to exactitude the age of the formation. Its position 

 relative to the other rocks of the island is also not well determin- 

 ed. It appears, however, always to underlie the great sandstone- 

 conglomerate formation which constitutes the major part of the 

 highlands of north-west Borneo. 



