~13¢
Although the fossil evidence does not avpear to afford decieive
evidence for either a Ladinian or Karnian age, it does seem to favour the
former. The possibility, however, of an age intermediate between Ladinian
P. archelaug and Karnian Trachyceras 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).

‘Bvidence of Stratigraphic Position

The evidence for the stratigrashic position of the Nathorstites fauna |
with relation to other faunas oan be examined. It has been recorded that
the Nathorstites fauna occurs in the 'Dark siltstones! and in the lower
part of the !Grey beds'; that a Middle Triassic (Anisian) fauna is present
in the upver. part of the Toad formation; and that the 'Flagstones! are mostly
barren but at one saeesbae carry brachiovods not unlike these in the -
Nathorstites fauna. It follows that no great range of strata lies between
the Nathorstites-bearinz beds and the beds with an Anisian, early Middle
Triassic fauna; at the most the range is that pibordea by the 'Flagstones!.
On the other hand, beds. of Karnian age are much higher in the section.
Mwo faunas overlie the Nathorstites fauna in the upper part of the Grey
beds!. The age of the Mahaffy Cliffs fauna is uncertain, but the age of the
higher, the poyana, fauna is almost certainly Karnian, and by no means late
Karnien, for the late Karnian Tropites fauna occurs in the everlying Pardonet
beds |

Although the ctraticrephic position of the Nathons ates HERS with

relation to other faunas offers no final proof of its age, it does weight

Hane ene ane in Payour of Hadi niarn time.

‘Alaska,

Martin (1926) has merented the presence of Spiriferina borealis
Whiteaves and Dawsonites canadensis Whiteaves from float on Hamilton Bay,
Kupreanof Island, Alaska. This occurrence, however, is not referred to by
Smith (1927). |

Frem limestone, a mile above the mouth of the Nation River, Alaska,

Smith (1927) lists Nathorstites alaskanus Smith, Trachyceras (Protrachyceras)

cf. lecontei Smith and other species. The species of Protrachyceras indicates