LOWER TRIAS : SPITI. 
19 
Thus from a faunistic point of view we can distinguish three subdivi- 
sions in the lower portion of the Lower Trias oi 8piti, namely, the 
Otoceras bed (1), the Ophicems bed (3), the Meekocems bed (4), each of 
them being characterised by the abundance — but not, as a rule, the 
exclusive occurrence — -of one genus of ammonite, which predominates 
in that particular horizon. 
Beds 7 and 8, which are separated in all sections studied by Hayden 
and A. v. Krafit, by a band of unfossiliferous rock from li to 4 feet in 
thickness from the lower division {Meekoceras bed), contain a fauna of 
uniform character, in which some species of Xenodiscus (especially X. 
nivalis Dien.), Hedensfroemia and FlemingUes predominate. For this 
liorizon the name of •• Hedenstroemia beds" or 'Zone of Flemingites 
Rohilla " has been proposed by A. v. Krafft. A rich fauna of this horizon 
was first discovered by C. L. Griesbach in 1883 8. E. of the village 
of Muth, anil its stratigraphical independence was recognised by Diener 
in 1895. 
The fauna of tlie HedenstrcEinia beds of Spiti comprises the 
following species of Cephalopoda : — 
Pleuronautilus Dieneri Krafit. 
Meekoceras pseudoplanulatitm Krafit. 
„ sp. ind. aff. pilato Hyatt et Siuith. 
„ cf. joharense Krafit. 
,, solitarium Krafft. 
Aspidites Muthianus Krafit. 
,, superbiformis Dien. 
,, nov. sp. ind. aff. superho VVaag. 
Koninckites Yiidishthira Dien. 
„ giganteus Krafit. 
Xenodiscus Kapil i Dien. 
,, Pur us ha Dien. 
,, nivalis Dien. 
,, nov. sp. ind. ex. aff. nivalis. 
,, cf. trapezoidalis Waag. 
,, asiaticus Krafit. 
Flemingites Rohilla Dien. 
Mufhensis Kraft't. 
,, fjriesbachi Krafit. 
c i ( 220 ) 
