BUCHICERATID &. 29 
The ventral lobe is very widely open at the base and longer than the 
first lateral lobe. The two arms are blunt and very small. The siphonal 
saddle is phenomenally short and broad, with a faint centran marginal lobe 
and an equally faint marginal rounded saddle on either side. The first 
lateral lobe is funnel shaped, broad at the base, short and narrowing 
rapidly to a bifid termination. The second lateral lobe is very much 
smaller and shorter, and entire at the end. The third lateral saddle is 
small, entire until a late stage, but becoming bifid later. Beyond are two 
small entire saddles and two corresponding lobes or what may perhaps be 
more accurately described as a bifid lobe and a bifid saddle. 
The first and second lateral saddles have internal ridges, but these 
coalesce, forming a short, flattened area along the mesal plane, which 
becomes deeply convex toward dorsum and venter. There are only two 
broad saddles and two narrow lobes on the dorsum, and these have no 
connecting ridges with the external saddles. The surfaces of the wings of 
the septa are strongly inclined inward, the outer sutures being considerably 
in advance or orad of the inner ones. This gives a remarkably concave. 
aspect to the wings of the septa on either side of the dorsum. 
The dorsal sutures, which were worked out with difficulty, show that 
the inner arm of the bifid fourth lateral saddle passes across the line of 
involution, coalescing with the third dorsal saddle. The antisiphonal lobe 
is asymmetrical, entire at the top, unequally serrated on the sides, and bent 
over to the left until the tips touched the inner angles of the first pair of 
dorsal saddles to the right of the mesal plane of the body. The first pair 
of dorsal saddles are deep and broad with broad entire bases. The first 
lateral lobes are small and unequally bifid, the sides being coarsely serrated. 
The second dorsal saddles are much inclined and obscurely tridentate or 
entire. The second dorsal lobe is very small and entire. The third dorsal 
saddle is a part of the fourth lateral, as stated above, and is entire. 
Vestiges of the shell were present upon this cast in a few places and 
showed coarse lines of growth. Unfortunately the shell covering the venter 
of the young whorl was chipped off in cleaning this part for drawing, and 
evidence of the statement made above with reference to the keel was lost. 
Locality: Cachiyacu, west side of Hullagua River, Peru. 
Age: Upper Cretaceous. 
