312 Messrs. A. H. Everett, J. Evans, and G. Busk. [Apr. 15, 



tions were carried on in twelve of these caves. The deposits con- 

 tained in them varied. A few afforded nothing but thick accumu- 

 lations of bats' or bird-guano still in process of deposition. This 

 deposit was examined in three instances, and proved to be perfectly 

 barren, with the exception of a few of the bones of the bats and swifts, 

 to which it owed its production. The commonest deposit in the caves 

 of Upper Sarawak was found to be an exceedingly tenacious, dark 

 yellow, homogeneous clay, which is sometimes crusted over with as 

 much as a foot of dry mortar-like stalagmite, and sometimes is itself 

 concreted into a kind of stony, pseudo-stalagmitic mass ; but more gene- 

 rally it occurs in the form of simple wet clay lying immediately on 

 the limestone floors of the caves and without any other deposit above 

 it. It occurs both at the water-level and in caves 150 feet or more 

 above it. Occasionally, as in some of the Bidi caves, it is mixed with 

 sand and fine water- worn gravel. It is evidently derived from the 

 waste of the clay shales and soft felsitic porphyries which now make 

 up the lowlands in the vicinity of the limestone hills — worn fragments 

 of these rocks occurring in it. I have very seldom met with organic 

 remains in this clay, notwithstanding that, in addition to my own 

 excavations, I have always been careful to search for bones in the 

 debris left by streams running through the caves and carrying away 

 the softer parts of the deposit. Such few remains as have presented 

 themselves indicate that the clay is of fluviatile origin. They com- 

 prise bones and teeth of pig and porcupine, a large part of the skeleton 

 of a Chelonian reptile, and numerous land and fresh-water shells. A 

 prolonged search would doubtless reveal remains from time to time, 

 but certainly not in sufficient abundance or of interest to warrant the 

 cost of exploration. 



In addition to the guano and clay, there was found in four instances 

 a regular series of deposits (in caves Nos. V, XIII, XXI, and XXXII), 

 of which the following note represents the section, as generalised from 

 the excavations in caves Nos. V and XIII. 



(1.) A surface layer of disturbed earth composed largely of char- 

 coal, rotten wood, and bamboos, with fragments of modern pottery, 

 glass beads, recent bones, quantities of fresh- water shells (chiefly the 

 common jootamides) , and other debris — being the relics - left by the 

 Dyaks, who camp temporarily in the caves when they are employed in 

 gathering the harvests of the edible birds' nests, which is done three 

 times annually. This layer is, in some cases, a mere film, but about 

 the entrance hall of No. XIII it was as much as a foot in thickness. 



(2.) A talus of loam or clay mixed with earthy carbonate of lime, 

 which locally forms a hard concrete, and crowded with the tests of 

 many species of recent land shells, together with the bones, generally 

 fragmentary, of various small mammals belonging chiefly to the order 

 Rodentia. This talus is composed, in great measure, of large angular 



