54 
DIENEU : TRIAS OP TtlE HIMALAYAS. 
been found in the Meekoceras beds of Idaho associated with a typical 
Lower Triassic fauna. But the American species, P. Arnoldi Hyatt et 
Smith,' is not identical with the Alpine form. The two distinguished 
authors are probably right in regarding it as a survival of the ancestral 
type, whose mature form is very much like the larval stages of 
Meekoceras. ■ 
I may be permitted to quote in this place a note from my memoir 
on the Permian fossils of the Central Himalayas {Paloeont. Ind., ser. 
XV., Himal. Foss., Vol. I, Pt. 5, p. 196) :— 
" A bed of peculiar interest is the Permian limestone, which south of 
Pomarang, is intercalated in the dark micaceous Ruling shales. It is 
rich in gasteropods and bivalves, and recalls the Bellerophon limestone 
of the South-eastern Alps. With the fauna of this remarkable horizon 
it has jirobably one species, Bellerophon Vigilii Stache, in common. The 
predominance of European Permian types in this limestone is an inter- 
esting fact. Three species of bivalves — Modiolopsis Teplofji Vern., 
Solernya biarmica Vern., Oxytoma latecostatum Netsch. — are identical 
with such from the Permian strata of Russia, whereas another one is 
most nearly allied to Conocardium siculum Gemm., from the Permian 
Fusulina limestone of Sosio in Sicily." 
Any attempt to include the Otoceras stage in the Permian system 
is contradictory to palaeontological evidence. It necessitates a corre- 
lation of the Otoceras beds with the Bellerophonkalk, to which their 
fauna has no affinity. 
On the principle of establishing correlation of horizons in distant 
countries by identity of the fossils all the evidence goes to prove that 
the Bellerophonkalk is the homotaxial equivalent of the Upper Pro- 
ductus Limestone and of the Kuling shales, especially of the limestone 
of Pomarang containing Bellerophon Vigilii, whereas the Otoceras stage 
corresponds stratigraphically to the lowest division of the Werfen beds 
(lower Seis beds). 
^ A. Hyatt and J. P. Smith : Triassic cephalopod genera of America, I. c, 
p. 130. 
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