TUIASSIC SEEIES. < 



limestones with Megalodon follow immediately above the infra-triassie 

 o-roup. These thin-bedded limestones are succeeded by quartzites and 

 dolomites of very considerable thickness, again overlaid, in certain 

 situations, by thiu-bedded limestones and slaty shales, which, on account 

 of their containing a different fauna, we have divided from the rest. 

 The group, therefore, presents two divisions, a lower one, consisting of 

 limestones and dolomites with Megalodon and Bicerocardium, and a 

 superior one, consisting of slaty shales and limestones with Nerinea. 

 In the lower division, at the apparent base of the whole triassic series, 

 and immediately resting upon the haematite, which we have provisionally 

 included in the group beneath, is a strong bed of limestone thickly 

 studded with large, sections of Megalodon, Bicerocardium, Gliemnitzia, 

 and Gervillia. The same or another zone,* also associated with haematitic 

 strata, contains similar fossils in a situation on the northern slope of the 

 mountain, which, if undisturbed, would occupy a place high up in the 

 formation. From the fossil sections exposed on weathered surfaces of 

 these beds the accompanying outlines were copied (fig. 1), it being 

 utterly impossible to get the impacted specimens out of the hard rock, 

 from which they do not separate. In other beds occur different organic 

 remains, principally uncharacteristic forms of bivalves and gastropods, 

 with RhyncUonellcR and very scarce and badly preserved Terelratulm, 

 possessing but little stratigraphical value. 



Were not the Megalodon and Diceroeardinm present, we would have 

 found it difficult even to ascertain the triassic age of the group. 



These genera are characteristic of the upper trias in Europe, and 

 in order to ascertain if they are the same here, we have to refer to the 

 geology of Spiti. 



Above the limestones there with Amm. Studeri, Sfc, representing 

 with great probability the Muschelkalk of Europe, Dr. Stoliczka 



* Wliich it is could not be easily made out, owing, probably, to obscure dislocation, 

 very possibly allowing the lower beds to be repeated. 



( 337 ) 



