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__The ‘Grey beds’ contain the Nathorstites fauna below, the Mahaffy
Cliffs and Red Rock Spur faunas near the middle, and the Lima? poyana
fauna at the top. A study of these faunas should furnish evidence of the
age of this unit.

_ The age and correlation of the Nathorstites fauna have been recently
discussed (McLearn, 1947A). Two species of this fauna in British Columbia,
Sptiriferina borealis Whiteaves and Dawsonites canadensis Whiteaves, have
been listed from float on Hamilton Bay, Kupreanof Island, Alaska (Martin,
1926). This occurrence is not recorded by Smith (1927).

Nathorstites alaskanus has been described by Smith (1947) from lime-
stone a mile above the mouth of Nation River, Alaska. This species shows
very little resemblance to any of the typical Nathorstites species of north-
eastern British Columbia.

The Nathorstites fauna has been reported from three localities within
the Arctic Circle; on the island of Spitzbergen, on Bear Island, and on
Kotelny Island. Nathorstites-bearing beds are present in the central and
eastern parts of West Spitzbergen Island and on the nearby Barents Islands.
They lie between the Daonella beds below and Rhaetic plant-bearing beds
above (Stolley, 1911; Frebold, 1935), and are said to contain several
species of Nathorstites of which one is in common with the Nathorstites-
bearing beds of northeastern British Columbia. On the east coast of
Bear Island, grey sandstone and dark shale with clay-ironstone concretions
carry a fauna with Nathorstites (Boehm, 1903). ‘They are the youngest
known strata on the island, and are underlain by barren sandstone. The
fauna of these beds includes Nathorstites mcconnelli var. lenticularis
Whiteaves and Dawsonites canadensis Whiteaves, in common with the
Nathorstites fauna of northeastern British Columbia. Nathorstites has also
been reported from Kotelny, one of the New Siberian Islands (Diener, 1916).

The Nathorstites-bearing beds of northeastern British Columbia may
also be correlated with the European and southern Asiatic Triassic suc-
cession, particularly in the Mediterranean and Himalayan realms, on the
site of the ancient Tethys seaway. Such a correlation has been briefly
considered by McLearn (1947A) and will be more fully treated in a later
publication on the Triassic.

Although the fossil evidence does not appear to afford decisive evidence
for either a Ladinian or Karnian age of the Nathorstites fauna in northeastern
British Columbia, it does somewhat favour the former age. The possi-
bility, however, of an early Karnian age or an age intermediate between
Ladinian P. archelaus and Karnian T’rachyceras time is not ruled out. It is
evident that some of the uncertainty arises from the similarity of the
P. archelaus and Trachyceras faunas, a similarity that has been noted by
Spath (1934).

The age of the Nathorstites fauna of Spitzbergen and Bear Island is
not necessarily the same as that of the Nathorstites-bearing fauna of north-
eastern British Columbia. Indeed, the recorded occurrence of Halobia
rather weights the evidence in favour of a Karnian and Upper Triassic age
of the fauna preserved at these northern localities.

The Mahaffy Cliffs fauna includes numerous species of pelecypods,
among them being Lima cf. striata var. lineata Schlotheim, Myophoria