6 
PALEONTOLOGY 
DESCRIPTION OF CANADIAN SPECIES 
Order, Ammonoidea 
Superfamily, Stepheoceratacea 
All the Canadian specimens (8) to be described come from a railway 
cutting through the Fernie formation, from two spots distinguished as 
Loc. 6591 and Loc. 6593, 1 Grassy mountain, Blairmore area, Alberta; they 
are in the collection of the Geological Survey, Canada, Victoria Memorial 
Museum, Ottawa, and were obtained by F. H. McLearn. The intractable 
matrix in which tbey occur has made the study and attempt to obtain 
suture lines particularly difficult. 
Family, Macrocephalitidae S. Buckman 
1922. Macrocephalitidae S. Buckman, Type Ammonites, vol. IV, legend of 
Plate CCLXXXIIL 
More or less of sphaerocones (ex cadicones?) passing to platycones. 
Overlap of whorls considerable; umbilicus relatively small. Venter rounded 
in all stages of growth. Ribs usually numerous. Suture-line sometimes 
showing a high degree of complexity, but with very little backward curva- 
ture of umbilical lobes. Simplification of suture-line is presumably a 
phylogerontic feature. Diminution of whorl-thickness and loss of ribs 
leading to complete smoothness are phylogerontic features attained by 
different genera independently of each other and independently, so far as 
the characters themselves are concerned — thus smoothness may appear 
before there has been much diminution of thickness of whorl or it may be 
delayed until after the diminution of thickness has become very pronounced. 
The attempts to place Macrocephalites in the family Pachyceratidae, 
as an early offshoot of that stem (8. Buckman, p. xiii), or to place it in the 
Sphaeroceratidae as a late development of that (S. Buckman, p. 22) are 
not satisfactory solutions. It is evident that Macrocephalites has been 
used to cover more forms than can be fitted into one genus, and that the 
forms attributed to Macrocephalites by Parona and Bonarelli and by 
Blake, to go no further afield, require separation into several genera which 
deserve a family name. 
Dr. Paul Lemoine (1910, 1911, pp. 28, 51) has given most useful 
bibliographic lists of the species of Macrocephalites ( = Macrocephalitids and 
Macrocephalitoids) . He has analysed these species according to their 
affinities and according to their genera, thus in many cases doing the great 
service to the reader of preventing him going on useless errands — very 
essential, considering how great is the number of works which have to be 
consulted and the difficulty in many cases of obtaining them. But it is 
safe to say that if Dr. Lemoine had had at his disposal more generic names 
1 Loo. 6591. Rook thrown out from railway cut in upper thin calcareous sandstones and shale, Grassy moun- 
tain, Alberta. Loc. 6593. Same as 6591. 
