Revieu'S — Geological Survey of India. 475 



ground ridge of older rocks along the valley of tlie Thames ; to Denu- 

 dations, and to Economics and Springs. 



In the Appendix there are accounts of 488 Well-borings, arranged 

 according to counties. To these Mr. Whitaker has added many 

 remarks of his own in regard to the classification of the beds passed 

 through ; and, together with accounts of 36 borings, they form a 

 most valuable record of facts. 



Other Appendices contain copious lists of fossils, minerals, etc. 



The whole work — embracing as it does a minute account of the 

 Chalk and Eocene Tertiaries of the London Basin — reflects great 

 credit on the author for the amount of valuable matter contained in 

 it, its admirable arrangement, and the facility of reference given by 

 the indexes to authors and localities. There are numerous woodcuts 

 illustrating the geological structure and features of the country. 

 The page illustrations would have looked much better had they been 

 printed on blank leaves ; and both type and paper might well be 

 of better quality. 



We may mention that the parts contributed by Mr. Bristow are 

 chiefly notes on the geology of Berks, Hants, and Essex, etc.; those 

 by Mr. Hughes are on the geology of portions of Kent. 



The various superficial deposits have been left for a second me- 

 moir, as they are as yet mapped in part only. This will complete 

 the geology of the important area called the London Basin. 



IV. — Eecords gf the Geological Survey of India. Part IL 



May 1872. 



ME. W. T. BLANFOED contributes some notes on the geological 

 formations seen along the coasts of Biluchistan (commonly 

 called Makran), and those of Persia from Karachi to the head of the 

 Persian Gulf, with observations on some of the Gulf Islands. Three 

 distinct systems of rocks are exposed in these localities, in descending 

 order : — 1. Littoral concrete (sub-recent) ; 2. Makran group (post- 

 Kummulitic ; 3. Hormuz salt formation (of unknown age). 



The island of Hormuz is a most singular place. It is almost des- 

 titute of vegetation, and consists of a mass of low craggy hills, 

 brilliantly coloured. Beds of volcanic origin, dolerites and trachytes, 

 rock-salt, shales and sandy-beds, are found interstratified, all belong- 

 ing apparently to the same series. The rocks are much disturbed ; 

 beds of salt and volcanic bands alike dip at high angles. There is 

 no evidence to determine the age of these salt beds ; but they are 

 clearly older than the Makran group, for in the Island of Hanjam 

 they crop out here and there beneath this group, which rests un- 

 conformably upon them. 



The prevailing rock along the Makran coast is a pale grey clay, 

 with bands of shelly limestone, calcareous grit and sandstone. It is 

 occasionally intersected by veins of gypsum, and contains numerous 

 marine fossils, many of which seem identical with species now 

 existing along the coasts. 



The mud volcanos of the Makran coast appear to consist of this 



