OF WESTERN SIND. 5 



A local break occurs to the south, and the Upper Nari beds rest unconformably on 

 the denuded edges of the Lower Nari brown limestones ; and still further south, fifty 

 miles east of Karachi, there is a well-marked distinction between the upper members of 

 the group with Orbitoides papyracea and the lower with Nummulites garansensis ; and 

 in one locality the upper member overlaps the lower, and rests on Khirthar limestone. 



To the east of the Laki range the Nari beds are wanting, and the Manchhar series 

 rests unconformably on the Khirthar, with some pebble-beds of the Gaj series inter- 

 vening. But to the west of the range the Nari and the Gaj series are found in their 

 normal sequence ; and towards the coast the exact distinction which can be drawn else- 

 where, stratigraphically and petrologically, between the Tertiary series is not possible : 

 this is mainly due to the disappearance of the limestone element of the Khirthar and 

 Nari series, and to the prevalence of sandstones and shales. The fossils, however, 

 distinguish the groups ; but the horizons of the zones of Nummulites and Orbitoides 

 vary, being higher or lower in their proper series according to locality. 



The upper sandstones of the Nari group have not yielded marine fossils, and in 

 Upper Sind they contain the remains of plants. 



The Nummulites become fewer in their species at the base of the Nari group, and 

 cease to be found in the lower beds of the succeeding series, the Gaj. 



The Gaj group, with a base of highly fossiliferous limestones and calcareous beds, 

 more or less shaly and stratified, overlies the softer shales and sandstones of the Nari 

 series. The development of the calcareous series is great ; but it is subordinate to an 

 arenaceous element. The sandstones are intercalated with clays with gypsum; and 

 shales and bands of limestone, highly coralliferous, are very constant. 



The Gaj series rests conformably on the Nari series ; although there is a minera- 

 logical break, the passage is so gradual that calcareous bands of the Gaj series are found 

 interstratified with the uppermost Nari sandstone. The Gaj series overlaps the Nari to 

 the south and rests on the Khirthars, and is wanting in Lower Sind to the eastward of 

 the Laki range. 



North-east of Karachi the series is highly developed, and massive limestones 

 occur ; they reach as far as the coast. 



The uppermost beds of the Gaj series are variegated clays and grey sandstones, 

 which form a passage into the overlying Manchhar strata, and contain species of 

 Ostrea, Corbula, Area, Scalaria, Buccinum, and Turritella. A crab of the genus 

 Typilohus and Vicarya Verneuilii have also been found there. The oyster is like 

 Ostrea multicostata. The Echinoderms are numerous. The Corals found, princi- 

 pally associated with the limestone-beds, are very difiierent in their aspect from those 

 of the underlying Nari group. They belong for the most part to reef-building 

 genera ; and some are represented in modern reefs by allied species, which grow in 

 the surf and in the most exposed parts. The rest were dwellers in quiet water. 

 Great masses of the coral limestone consist of Stephanocoenia maxima in casts ; and the 

 presence of the genera Madrepora, Haliastroea, and Porites is very significant of 

 shallow-water conditions. 



' Besting on the Gaj strata is the Manchhar group ; and where the Gaj beds are 



