276 EXPLOKATION OF THE CAVES OF BORNEO. 



foot of dry mortar-like stalagmite, and sometimes is itself con- 

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

 generally it occurs in the form of simple wet clay lying immediate- 

 ly 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 felsi- 

 tic porplrvries 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, notwith- 

 standing that, in addition to my own excavations, I have always 

 been careful to search for bones in the ctibris left by streams 

 running through the caves and carrying away the softer parts of 

 the deposit. Such few remains as have presented themselves indi- 

 cate that the clay is of fluviatile origin. They comprise 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., XILL, XXI., 

 and XXXII.), of which the following note represents the section, 

 as generalised from the excavations in caves Xos. Y. and XIII. 



(L.) A surface layer of disturbed earth composed largely of 

 charcoal, rotten wood, bamboos, &c, with fragments of xiiadern 

 pottery, glass beads, recent bones, quantities of fresh-water shells 

 (chiefly the common pofamidss), 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 kvver 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 earthly carbonate of 

 lime, which locally forms a hard concrete, and is crowded with the 

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

 generally fragmentary, of various small mammals belonging chiefly 



