IX 
good forward sweep over the venter and it differs in suture-line — EL is just 
shorter than LI and LI has not such a long — terminal lobule; then SI is 
much shallower than ES (external saddle), consequently though L2 is 
about the same length as in the present species it occupies a different 
position on the shell, and so instead of ending at about or rather before 
the line of the inner lobule of the tridactyloid ending LI it comes below it 
and extends to the guide-line: in P. glabrescens L2 ends well short of the 
guide-line. The proportions of the suture-line of Pompeckj ’s species 
taken from his figures are approximately: 
Proportion of whorl-breadth of 29 mm., 
EL 41*5, LI 34*5, L2 28 per cent 
Proportions on whorl-curve of 39*5 mm., 
EL 30, Ll 25, L2 20 per cent 
As both ornament and suture-line of Pompeckj ’s species differ from those 
of the Canadian shell, it cannot belong to the same lineage as Paracephalites. 
On the same grounds it is not truly a Macrocephalites , though it is one of 
the Macrocephalitidae. 
Pompeckj claims (X, p. 72) that the example figured by Newton and 
Teall (PL XL, fig. 3) from the same locality by the name “ Macrocephalites 
ishmae, smooth variety” is another example of his M. koettlitzi . The 
estimated proportions of the specimen are, F.66, 56, 55, 6?: the whorl is 
broader and the umbilicus smaller than in Pompeckj ’s species. 
With the costate stage of P. glabrescens may be compared Macro- 
cephalites tumidus: Nikitin, 1881 (PL X, figs. 18, 19), from Russia. It is 
laterally flexiradiate and has a suture-line with an outer portion similar 
but rather more elaborate and an inner portion very much more elaborate. 
Proportions of conch are similar — the figures give F.70, 48, 54, 18*5. 
Ammonites tumidus Reineeke (PL V, f. 47, 48) has similar proportions— 
they are approximately F.48, 50, 55, 18; but it is quite a different shell 
from Nikitin’s and from P. glabrescens : it is recticostate and has indica- 
tions of a highly developed suture-line. 
Genus, metacephalites nov. 
Genoholotype, Metacephalites metastatus nov. 
A Macrocephalitoid, distinct from Macrocephalites and from Para - 
cephalites by simple suture-line and by ribs curving forward on venter. 
The primary ribs are curved, small, approximate, mostly breaking into 
three secondaries, one of which, however, is obscurely joined or is inter- 
calate. Curvature of ribbing over rounded venter is slight and becomes 
less with growth. The ribs are raised but not laminate. The suture-line, 
obscurely shown, however, seems to be distinguished by its simple character 
and by a quite short, broad superior lateral lobe (Ll) (See Plate III, 
figure 1). 
Metacephalites metastatus nov. 
(Plate III, figures 1-4) 
Holotype No. 6098; loc. 6593, Grassy mountain 
Proportions, S. 30*5, — , 46 — ; 43*5, 48, 50, 18. Length of Ll at 
13 mm. c.40 per cent 
77865—3 
