one of the Sandwich group, 18 



hollows, with the deep lava soil at bottom, and a running stream 

 in the middle. At first sight the lava soil appears to be a fertile 

 black mould, but it is nothing more than an accumulation of 

 round gravelly grains of lava rock. 



Stratification. — There were tendencies to this in some cra- 

 ters at the east end of the island, and at the plain of Eva, 

 near Pearl River, at the salt lake ; but these I had no opportu- 

 nity of examining. The only distinct traces that I observed 

 were on the north-east coast, near Waihea. I there met with 

 specimens Nos. 13, 17, and 29- It consists of an alternation of 

 beds of dark coloured compact basalt rock, from one to six feet 

 thick, alternating with still thicker beds of grey colour, tufface- 

 ous and amygdaloidal rock, different from any seen in other 

 parts of the island. One of the beds (No. 17,) could not be dis- 

 tinguished from some kinds of greywacke slate in texture and 

 colour of the basis ; it contains disseminated numerous white 

 points, which are probably crystals of calcareous spar. No. 14, 

 is not unlike some kinds of wacke. The basis of Nos. 15, 16, 

 29, is nearly the same as 14, but contains larger amygdaloidal 

 cavities. The whole of this series of rocks is directed N. 55° W. 

 by compass, nearly parallel with the general direction of this side 

 of the island, and the dip to the north-east, rising to the centre 

 of the island. One of the most likely modes of accounting for 

 the formation of these strata, which differ so much from any of 

 the other rocks of the island, is to suppose that they were up- 

 raised at the time of the elevation of the central masses of Oahu. 

 Whether the basalt ought to be included in this category, or 

 ought to be viewed as a vein traversing the other beds, and 

 standing in connection with the lavas of the interior, is doubt- 

 ful. This relation would merit further examination. The only 

 other place where I saw symptoms of stratification, was in the 

 bounding walls of some crater-shaped ravines in the vicinity of 

 Panalau, to the west of the promontory of Kualoa. These 

 seemed to dip regularly outwards on all sides, from the crater, 

 of the position, of which they gave the most indubitable evi- 

 dence. Some appearances of the same nature were seen in the 

 bounding hills of the salt lake, on the opposite side, and in some 

 of the craters that we passed at sea, at the west extremity of the 

 island. 



There can be no doubt that the lateral ridges, descending with 



