1842.] Bijapore to Bellary via Kannighirri. 947 



laterite. It is not so soft interiorly. This paste adheres to the tongue, 

 and gives out an argillaceous odour when breathed on. The more com- 

 pact parts of the rock, forming the coating of the tubular cavities, 

 become magnetic before the blowpipe, and are converted into a dark 

 grey slag. 



Proceeding in a S. E. diretion by Jawannaghi and Narsinghi, to Alcopa, 

 From Bagwari to Al- a villa S e east of Umblanur, the road lies diago- 

 c0 P a - nally across the low trap swells which have gene- 



rally a S. W. direction, though their lines sometimes intersect each other 

 at obtuse and acute angles. The tops of the swells are mostly slightly 

 convex, though often terrace-like, and are composed of the more com- 

 pact and globular trap. In the banks of nullahs, the trap and amygda- 

 loid may be observed alternating, and passing into each other : when 

 they occur horizontally, the trap is generally the surface rock ; this may 

 be owing to its superior hardness, and capability of withstanding the 

 abrasions caused by the elements. The amygdaloid contains irregular 

 bits of decaying felspar and numberless vesicles, often filled with green 

 earth and crystals of carbonate of lime. The former mineral, in moist 

 situations, assumes a black or deep brown colour in decomposition, 

 giving a speckled appearance to the rock, resembling that of the toad- 

 stone of England. Before the blowpipe, these dark spots are converted 

 into black slag. In the bed of a stream, a few hundred yards N. W. 

 from the village of Kunkal, I found slender prismatic crystals of carbonate 

 of lime fasciculated in sheaf-like forms, with dark pieces of chert in a 

 friable mass of the amygdaloid ; the radii of the calcareous crystals were 

 three inches in length, and of a faint amethystine hue. 



About two miles to the north of this village, indications of a change 

 in the formation were seen in the angular bits of red pegmatitic 

 and quartz rock, that occur on the plain and in the beds of nullahs, 

 which become more frequent as the villages of Kunkal and Alcopa 

 are approached. A few hundred yards south of the latter, I found these 

 indications confirmed, and the quartz rock in situ, in tabular masses in 

 the bed of a nullah. Alcopa is situated near the south-eastern foot of 

 a slope, on the top of which the trap has the usual compact and globular 

 form ; while at the base it is tabular, schistose, and amygdaloidal. A 

 few hundred yards to the south of this village, the trap formation ceases 

 at the foot of a low range of flat- topped hills of sandstone. In the hope 



