Valley ofOod'ipoor. 279 



fine schistose, include numerous scales of mica, and frequent- 

 ly form a rock, which may be described as intermediate be- 

 tween clay and mica slate. In some of the varieties, occasional 

 laminae of calcareous spar are observed ; these last are the 

 calschistes of the French. Proceeding west we have still argil- 

 laceous schists of different kinds, alternating with talco-argilla- 

 ceous schists, silico-argillaceous schists, and occasionally with 

 quartz-rocks similar to the quartz of the barrier range. The 

 route lies over an uneven rocky plain, with alternate low ridges 

 and hollows, corresponding with low ranges observed on our 

 right and left, which are separated from each other by narrow 

 longitudinal valleys. We then enter upon the irregular mam- 

 mil lated plain, constituting what is usually termed the Valley of 

 Oodipoor. 



To describe all of the modifications of argillaceous schist 

 which we observed on the route we have just traversed, would 

 extend this paper to an undue length. On referring to a de- 

 scriptive catalogue of specimens from this part of the country, 

 deposited by me in the Museum of the Asiatic Society of Cal- 

 cutta, I find that the varieties are very numerous, and that I 

 have arranged the principal under one or other of the following 

 heads; namely, talcose schist (found only in one locality), — 

 argillaceous schist, — rocks intermediate between talcose and ar- 

 gillaceous schist, — between chlorite and argillaceous schist, — 

 between micaceous and argillaceous schist, — between quartz- 

 rock and argillaceous schist, — and between greenstone and 

 argillaceous schist. Some of the argillaceous schists approach 

 to the nature of roofing slate, but this is rare. The talco- 

 argillaceous schists are the most numerous ; these are gene- 

 rally soft, have a soapy feel, more or less prominent, a lustre 

 inchning to silky, and a fine schistose texture. The mica- 

 ceous-argillaceous schists are also common, and rocks allied in 

 their nature to chlorite-schist are by no means rare. The strata 

 as yet observed are arranged in a nearly vertical position, and 

 though some, especially of the softer kinds, exhibit partial bend- 

 ings, their general course may be stated to be rectilinear. The 

 strata of the plain and lowlands are, on the other hand, much 

 distorted. It is not generally practicable to trace for any dis- 

 taoce thd rocks wWchi now preisent themselves. The surface 



