L. 25, P. 8 Went exploring with the dinghy down the river a way this afternoon. First stop right bank half way down the E-W stretch in front of camp. The tip of the peneplain reaches the river. Clothed with good forest, with savanna on either side, the savanna east of it distinctly on lower ground, some fifteen feet lower, the peneplain being around 30 feet above high tide level. No rock outcrop. Next stop on the outside of the bend at the end of the S-W reach, where river turns S. Here also the peneplain, some twenty feet higher than tide-top turns the stream. Also heavily forested, with savanna some eighty yards back from the water. Thus this "rain-forest" can be classed as gallery woods. Just before river reaches bend, a creek filled with mangrove growth enters from N. Third stop, on N bank about one third of way back to camp. Steepish bank with the peneplain atop. Here decomposed limestone outcrop, and distinct ledges visible down through the water, looking like beds of limestone some ten inches or so thick. Shall revisit place at low tide to get strike and dip and specimens. Apparently when the river cuts against the peneplain it almost always induces a strong forest development. Probably the effect is only indirect, and due more to improved drainage and sweetening of the soil; for according to Brass the soil of the savannas is strongly sour inspite of its underlying country rock of limestone. At any rate the picture consists of an erosion-etched peneplain, much of which is entire, slightly lowered in general level to allow entrance of the sea into the principal river and creek-beds, but with the top of the limestone generally some feet above high tide level. The broad, flat, surface expanses of the peneplain are now sour and support only tree-savanna, while the better drained portions carry forest whose largest trees reach two to three feet in diameter. Along the river faces in the actual tidal fringes mangrove and nipa palm grow, the nipa usually along the insides of bends. Decomposition materials overlying the limestone vary in thickness from five to fifteen feet. Lateritic nodules apprea in many places on the surface. Some iron stains can be seen in the limestone itself. Temperatures: min. 23 c., max. 33 c. Rains by 3 oclock, thundershowers. Fri. Dec. 18. Rain for most of night. Went back at low tide again to examine limestone outcrop seen yesterday. Rock much decomposed; parts stained brown, Beds where first seen apparently levely but 30 yards to W a 20 degree incline clearly seen, so probably exposure in toto represents the western half of an anticline with strike more or less N. Took several specimens of the rock. Catch with the rat traps: 8 ringeas, 1 brachyrhinus. The steel trap artists though they did not get Echimypera_ yet brought me the first fully grown Uromys for the station. Radio from Austen, Daru saying "Vailala"unable leave till early in new year because of magneto trouble. Took dinghy and went up main river this morning. Found limestone outcrop in two other places. Took bearings and number of notes which have put on map (see later). Going tomorrow up SW branch to do likewise. Hope by compiling all data to have fair amount of evidence re surface geology of the near-by country. On second thoughts have decided to transcribe notes from rough map: the main river, or as I'm told, the Baura Kussa turns in a broud swing of a quarter of a mile in diameter, leaving the West "reek, to a NE stretch about 1/4 mile long; then bends to due N for another 1/4 mile; then a couple of hundred yards NNW; and around to the right entering a 1/2 mile stretch bearing 80 degrees or parallel with the top reach of the Wassi Kussa. I did not go up that stretch very far. Now coming down river, turns are started or else completed with the peneplain at the west end of the 80 degree stretch, the forest there being mainly tree-savanna. Rounding the bend a creek enters from the west, its mouth mangrove-filled, and just