86 PSEUDOCERATITES OF THE CRETACEOUS. 
EULOPHOCERAS NATALENSE n. sp. Hyatt. 
Pl. XI, figs. 2-6. 
This species is founded upon a fragment in the collection of the Yale 
Museum. Itis a bare cast on one side with the shell preserved on the 
opposite, right side, and on venter. Diameter, partly estimated, is 164 
mm. (actual diameter 155 mm.). There is no umbilicus, this being practi- 
cally sealed up by the growth of shell on one side, and is of course very 
small, where cleaned out on the other side. ‘There are faint folds on both 
shell and cast. The folds occupy the sides and are not confined to the 
outer or inner parts of the lateral surfaces, although more prominent along 
the centran lateral lines. 
The keel is solid in the younger stages (Pl. XI, figs. 5, 6) and then 
becomes apparently hollow. The proof of this is not absolutely clear, but 
in each volution of the section there is a partition of shell outside of the 
siphuncle. In the upper tip of the section of the volution next to the last 
a partition was also present, but this is apparently a section of the septum 
itself, and what seemed to be the siphuncle is represented on the right and 
above this partition. If this be correct the keel is solid at this age and 
remains in this condition in the last volution. The siphuncle is not present 
in this last volution, but as in the section of the next younger volution 
above described the common matrix fills the interior completely and on the 
outer exposed edge the sutures run against the solid interior of the thick 
deposits of the keel. In the younger whorls the space between the parti- 
tion above the siphuncle and the keel is filled, as in the interior of the 
siphuncile, by dark transparent calespar. There is, however, no black layer 
present above the siphuncle, as in the Jurassic forms, that have hollow keels. 
The sutures are extraordinary. They are so excessively overlapped 
that there are two second lateral lobes telescoped into every third one, so 
that one has to disentangle the lines of three consecutive sutures in marking 
out this lobe. It becomes necessary, in fact, to infer outlines that can not 
be seen, the sutures having in some parts necessarily passed along the 
same lines and can not be separated by the eye. The first to third lateral 
saddles are broad and have numerous long tongue-shaped marginal saddles. 
The fourth lateral saddle is also broad, deeply bifid, the outer arm entire, 
the inner bifid. About half of a volution earlier this saddle is much nar- 
rower, and is probably still smaller at younger stages. The fifth is also a 
