-~lo-~

based on drawings, are not faithful reproductions, and so errers may enter
into interoretations based on them. It is also vossible that comparison of
Giavnsedicn svecimens with actual foreign svecimens would result in the
recognition of more foreign and fewer new sovecies in the Canadian faunas.
It is not known what vercentsze of species would be so effectcd, but it is
exvected that this vercentaze would be small,

In the following pages, early Ladinian refers to Protrachyceras reitzi
time, late Ladinian to Protrachyceras archelaus time, early Kernian to

Trachyceras time, and late Karnian to Tropites subbullatus time.

Genus Nathorstites Boehm

The svecimens of this genus in northeastern British Columbia exhibit
@ wide range of variation. Whiteaves! inclusion of all the specimens
available to him in the McConnell collection from Liard River in one species,
namely Nathorstites neconnell ia was fully justified. Inclusion in the same
svecies of all the specimens recently collected from nuxjerous localities
in northeastern British Columbia Bposans to.be equally justified... Whiteaves!
separation of some svecimens as var. lenticularis is recognized; indeed
the svecimens of this variety outnumber those of the typical svecies.

Nathorstites can be briefly described as follows: stout, wide, broadly
fastigate, fairly involute inner whorls, with, in some svecimens, short
folds on the inner part of the sides of the whorl, ~ass sradually into a
mature stage of more compressed, smooth, completely involute, sharp-ventered
whorls; that is, in growth, tne shell passes from sphaerocone to oxyconer
The suture line is ceratitic and multisellate, with short, somewhat 'club-
shaved! saddles.

In the tyvical species, Nathorstites mceconnelli Whiteaves, the inner
whorls are wide and stout and the advince to oxycone is only partial. In
the variety lenticularis Whiteaves the oxyconic shape is fully attained,

Some variation in the course of the growth lines is observed, In all
soecimens it is convex forward on the sides of the whorl. In the holotype
and some other specimens it is projected forward as it approacnes the

venter; in others it curves a little backward (rursiradiate) at the venter.