or WESTERN AND CENTllAL INDIA. 5 



the basaltic rocks of Catch* unmistakably belong to the Deccan trap 

 series. This carries the western boundary as far west as longitude 69.° 

 The beds in Cutch are about 2,000 feet thick. I have also discussed 

 the possibility of the small section of amygdaloidal basalt which occurs 

 at the base of the nummulitic rocks at Runneekotef in Sind belono-ino'to 

 the same series, and have pointed out the possible connection of some 

 of the volcanic rocks found on the coast of Arabia by Dr. Carter. 



Independently of Sind, we have thus good evidence of the ex- 

 tension of these volcanic rocks throughout 2\ degrees of latitude and 15 

 of longitude. The area covered by them in the Peninsula of India can 

 be little less than 200,000 square miles. 



3. — Petrology. — Next, as regards mineral character. The most strik- 

 ing peculiarity is the great prevalence of amygdaloid, in which the 

 kernels, containing chiefly zeolite or agate, sometimes form the principal 

 part of the rock. The most common zeolitic mineral occurring is Stiliite 

 next in abundance are Apophyllite, Heulandite, Laumonite, and Mesotype 

 or NatroUteX- Chalasite and Thomsonite are rare. Analcime, which is said 

 to occur by some writers, I have never met with. 



Usually the nodules, both of zeolite and of agate, (the two frequently, 

 though not always, being found in distinct beds of trap,) are surrounded 

 bj' a layer of green earth, the great prevalence of which mineral is 

 extremely characteristic. , 



* See Captain Grant's map; Geol. Trans. Ser. 2, Vol. V, pi. XL VI. 



t See ante, p. (5). 



X The Rev. Professor Haughton's species Sislopite (Phil. Mag. 1859, Vol. XVII, p. 16 ) 

 is evidently merely Calcite, coloured by green earth, and, of course, no more a mineral 

 species than Fontainebleau sandstone is. See also Dr. Carter's note to a paper by Mr. Hislop 

 in Jour. Bombay Br. Roy. As, Soc, Vol. VI, p. 194. It remains to be seen whether the 

 Syhedrite of Professor Shepard, American Journal of Science for July, 1865, Vol. XL, 

 p. 110, is not Stilhite, coloured in the same manner. In any case the name ought to be 

 Syhadrite from the Syhadri, the range known in English by the absurd title of the Western 

 Ghats. 



( 141 ) 



