CORALLIFEROUS SERIES OE SIND. 



197 



merate near the base. In the Yero plain, running southward along 

 the eastern side of the Laki range, south of Banikot, large frag- 

 ments of silicified wood are common, and some trunks of trees are 

 upwards of 30 feet in length and 10 in girth. In the south, near 

 Karachi, the Manchhars pass into Gaj strata, and marine fossils are 

 associated with the lowest beds. 



The general conformity of this great tertiary series is evident — 

 although local unconformities occur, and there is evidence in 

 favour of there having been some disturbance of the older rocks 

 before the deposition of the Lower Manchhar group. The sub- 

 sidence which took place during the deposition of these thick shallow- 

 water deposits was vast ; and there were occasional slight upheavals* 

 The final epoch of the mountain-formation occurred after the depo- 

 sition of the Manchhars. The strike of the chains is in the main 

 north and south ; and the thrust came from the west to the east, and 

 from east to west. 



The date of the grand mountain-formation is subsequent to the 

 deposition of the sedimentary strata forming the Upper Manchhars. 



III. General Results of the Study of the Corals of the Series. 



The Corals of the strata with Cardita Beaumonti below the trap, 

 are shallow-water forms ; and their development indicates conditions 

 unfavourable to vigorous coral-growth. There was no reef. The 

 species are new ; and there are no characteristic Cretaceous or Eocene- 

 forms present. The Smilotrochi and the Rhabdophyllice are Secondary 

 genera; but the first-named had species in the European Tertiaries, and 

 may be represented in the shallow seas of the present day. The Cary- 

 ophyllice of the deposit have four cycles of septa only ; and this gives 

 them somewhat an ancient look ; and the Litharcea would pass either 

 as a Cretaceous or as an Eocene form. 



The fauna as a whole is deficient in characteristic forms, and may 

 be considered transitional. 



It has been stated by the Geological Surveyors that the trap re- 

 sembles the Deccan and Malwa trap; and the position of that vast 

 outburst is anterior to the Nummulitic age, and subsequent to some 

 Cretaceous strata in Western Central India. Certainly there are no 

 Nummulites in the sands and shales which contain the fossils ; and 

 these are the remains of a Cretaceous crustacean. 



The Corals of the Eanikot group are numerous in genera and 

 species ; and the fauna is remarkable for the number of simple forms 

 it contains, and for the predominance of the family Eungidse. 



The compound Corals of the family Astrseidse, which so largely 

 enter and have entered into the composition of reefs, are but feebly 

 represented ; and the few species which have been described did not 

 aggregate to form massive limestones, but were seated on small flat 

 circular epithecate bases. Eine as were many of the growths, yet 

 it was a stunted Coral-fauna; and the shape of the majority of the 

 forms would rather indicate that they lived in still water, and not 

 in the rush of the waves. Certainly the Corals were beyond the 



Q. J. Gr. S. No. 146. p 



