388 JAMES PERRIN SMITH 
division, or Middle Trias, communication had been opened 
between the Mediterranean and the Indian regions; thus in the 
Bosnic substage some faunal elements of the zone of Ptychates 
rugifer are common to both regions. From that time on the 
Triassic faunas of these two regions show strong resemblances to 
each other. The connection of the Indian with the Arctic region 
continued, but was growing less marked. 
The writert has demonstrated that the Arctic-Pacific region 
could hold good only for the Lower Trias, and that during 
the Upper Trias, Tirolic series, the faunas of California were 
nearly identical with those of the Himalayan and Alpine prov- 
inces, the zone of Tvopites subbullatus being clearly defined and 
with nearly identical faunas in all three regions. 
fe Lhuswine hirolicguimertie Arctic-Pacific sea, or Arctis, 
must have been broken up, and the faunas of the Mediterranean 
region, or Thetys, must have mingled with those of the great 
ocean. But that there were other Triassic regions, at present. 
unknown, is seen from the fact that Zvopitid@ appear suddenly 
in great numbers and without local ancestors during the 
Karnic stage of the Upper Trias in both California, India, and 
the Alpine province. The province where the 7vopitde origi- 
nated is as yet unknown, but it probably lies outside the Mediter- 
ranean, and somewhere within the Arctic-Pacific region. 
SUBDIVISIONS OF THE TRIAS. 
SCYTHIC SERIES. 
Brahmanic stage. — The lowest series of the Trias was named 
by Waagen and Diener? from the region of its most typical 
development in Asia. It is divided into two stages, the Brah- 
manic and the Jakutic. The Brahmanic stage is further divided 
into two substages, an oider or Gangetic, and a younger or 
Gandaric. The Gangetic substage is known only in the Hima- 
layas, where it is represented by the Ovsoceras beds, or zone of 
Otoceras woodwardi, the fauna of which consists chiefly of 
< JoURNAL GEOL., Vol. II, No. 4, pp. 375-376. 
2 Entwurf einer Gliederung der pelagischen Sedimente des Trias-Systems, p. 8. 
