Apr. 1899. PALEONTOLOGY OF UPPER CRETACEOUS SERIES—LOGAN. 209 
petuate racial characteristics. That these suppositions do not accord 
with the facts is a further confirmation of one of the laws of evolu- 
tion. Itis confirmatory of the law that as characters of development 
first show themselves in the adult, so also do degenerative characters. 
In other words degeneration takes place in the inverse order of 
development. The order of development of the Cephalopods, as 
shown by Hyatt, has been in regard to form: 1. the straight shell ; 
2. the arcuate shell; 3. the loosely coiled shell; 4. the closely coiled 
shell. Along with this development of the form of the shell has 
gone an increased development in the complexity of the sutures. 
Scaphites is considered degenerative in form because of the tendency 
exhibited in the adult to return to an early form by a partial uncoil- 
ing of theshell. If this be true degeneration, it hasnot as yet affected 
the sutures. 
In fact the phylogeny of the genus reveals progression rather 
than retrogression. As an illustration compare the suture of Scaphites 
warrent Meek, Fig. 1, Pl. XXII with the suture line of Scaphites no- 
dosus Meek, Fig. 2, Pl. XXII. 
The first is a Benton species while the second is a Pierre species. 
The first, therefore, is the primitive form as regards time and suture. 
Furthermore the ontogeny of S. zodosus reveals a stage which cor- 
responds with reference to the suture very closely to the adult suture 
of S. warreni. It seems very probable, then, that the latter is in the 
line of the direct evolution of the former and represents an earlier stage. 
The changes in form as revealed by the two species do not point to 
any marked degree of retrogression. The principal changes have 
been an increase in the size of the individual; an increase in the 
complexity of the suture lines; and the development of two rows of 
nodes, one on the umbilical shoulder and a second on the ventral 
border. In S. warrent the ornamentation consists of strong ridges 
with a tendency toward nodosity in some individuals. In the young 
of S. modosus the ridges are well marked while the nodes are entirely 
absent on the umbilical shoulder and not prominent on the ventral 
border. 
In the excellent work of Branco although Scaphites is mentioned 
in the list of genera its ontogeny is not exhibited. The omission was 
no doubt due to a lack of workable material. And, indeed, this was 
at first a serious obstacle to the success of the present writer. Owing 
to the highly crystalline character of the calcium carbonate which 
preserved the form of the shells many specimens were broken up 
without resuJts. Later, from some young forms furnished by Prof. 
Weller, of the University of Chicago, the results recorded below 
