122 PSEUDOCERATITES OF THE CRETACEOUS. 
both younger and older than the one drawn. he dorsal sutures could be 
seen only from above and in a fragment of the cast of the last camera, 
which is not included in the figures given. It was evident that the 
antisiphonal lobes resembled those of M. swallovi and Heinzia in being 
elongated and considerably telescoped into each other. The saddles also 
were similar, especially the first dorsals, which were narrow, long, 
phylliform, and deeply cut: into by the marginals, as in Heinzia matura. 
There was also a similar broad pair of second lateral dorsal saddles; these 
certainly had one marginal lobe and perhaps two, being perhaps trifid, but 
very flat on their bases. The remaining saddles were entire. There were 
apparently five saddles and four lobes on the right side and six saddles and 
five lobes on the left side, corresponding to the differences in number of 
the external auxiliaries on the same sides. The overlapping of the sutures 
is noticeable in this specimen, but whether it can be considered 
characteristic of the species is doubtful. The whole diameter is 85 mm. 
The last volution on the face of the septum from the center of the venter to 
the line of involution is 50 mm.; the ventro-dorsal diameter is 35 mm. 
The amount of involution at this point is two-thirds of the breadth of the 
side of the next inner volution, being 17 to 27 mm. The umbilicus, in 
consequence of the smoothness of umbilical zones and the nonextension of 
the cost internally, has a smooth, funnel-like aspect, entirely distinct from 
that of M. swallovi, although it is nearly of the same size and differs 
therefore from that of white? in being much larger as well as smoother. 
Locality: Texas. 
Age: Colorado epoch. 
METOICOCERAS WHITEI n. sp. Hyatt. 
Pl. XIU, figs. 3-5; Pl. XIV, figs 1-10, 15. 
Buchiceras swallovi White, 1875, Geog. and Geol. Expl. and Surv. West of 100th 
Meridian, Vol. IV, p. 202, pl. 20, figs. 1 a-c. 
Buchiceras swallovi Stanton, 1894, Bull. U. S. Geol. Survey No. 106, p. 168, pl. 37; 
pl. 38, figs. 1-3. 
The external characteristics of this species, in comparison with MM. 
swallovi, consist in more compressed volutions without such prominent 
nodes on the umbilical shoulders. They have nodes, but these are more a 
part of the costee and less prominent, the sides are consequently flatter 
than in swallovi. ‘There is a decided tendency in the Texas specimens to 
