HYDASPIAN STAGE OF WAAGEN. II 



Muschelkalk in the Central Himalayas (horizon of Ptychites rugifer). 

 u The triassic limestones of Chitichun may therefore be considered 

 as forming a lower division of the Indian Muschelkalk, corresponding 

 probably to the horizon of Sibirites prahlada in the main region of 

 the Himalayas l" 1 



Hydaspian stage of Waagen. — It is only with some reserve 

 that this view can be maintained, since Waagen has called attention 

 to the geological importance of his " Hydaspian " stage, comprising 

 the upper Ceratite limestone in the Salt Range, which he considers 

 to be the lowest division of the " Dinarian ,J series. 2 The triassic 

 limestones of Chitichun may eventually turn out to be homotaxial 

 with the upper Ceratite limestone of the Punjab, not with the lower 

 Muschelkalk (horizon of Sibirites prahlada) of the Central Himalayas. 

 From the latter a small number of brachiopoda, but only a single 

 ammonite, Sibirites prahlada, is known, and this is entirely different 

 from any species of Sibirites described by Waagen from the upper 

 Ceratite limestone. No direct comparison of the faunas of these 

 two stratigraphical horizons is therefore possible. 



From the upper Ceratite limestone of the Salt Range 41 ammonites 

 have been described by Waagen. among which 35 are Trachyostraca 

 and 6 only Leiostraca. In the triassic fauna of Chitichun on the 

 other hand, not less than 12 among 15 ammonites are Leiostraca. 

 Thus a direct comparison of the two faunas is likewise difficult. 

 Although identical, species are not present, the occurrence of a 

 species of Aspidites in the Chitichun fauna is in favour of its being 

 possibly homotaxial with the upper Ceratite limestone. Nevertheless 

 its bathrological position is as yet very uncertain. This uncertainty is 

 still strengthened by the rather conflicting characters which the 

 Chitichun fauna exhibits. The occurrence of geologically old types 



1 Pal. Indica, ser. XV Himalayan Fossils, Vol. II, pt. 2, Cephalopoda of the Mus- 

 chelkalk, p. 118. 



2 E. v. Mojsisovics, W. Waagen, C. Diener, Entwurf einer Gliederung der pelagischen 

 Sedimente des Trias-Systems, Sitzungsber. K. Ak. Wiss, Wien, math. nat.Cl. Vol. CIV, Abth. 

 1, Dec. 1895, p, 1289. 



( n ) 



