ICIITHYOSA UR IA FROM THE 
114 
Case. Shelf. Specimen. 
II c 6—18 
19—21 
22—23 
24 
b 1—16 
phalange bones, rounded at their adjacent 
margins, with irregular surface, as though 
separated by cartilaginous substance, 
parts of the hyoid arch. 
right and left femora. The femur is about two 
O 
thirds of the length of the humerus, 
undetermined. 
fragments of ribs, some nearly entire. They 
show the double head and the longitudinal 
groove characteristic of the genus. 
II c 
1—11 
12—14 
16 
17—19 
20—30 
31—32 
33—45 
46—54 
On this shelf is an associated series of vertebrae 
of a new species of Ichthyosaurus from near 
Peterborough (Porter Collection), 
are cervicals, with the upper head for the rib 
partly on the neurapophysis. c 9 is uncom¬ 
pressed and shows the tubercles for the ribs 
to be close together, indicating a different 
species from Ichthyosaurus dolichodeirus. 
c 15 is also cervical. 
are very early dorsal, the upper head for the 
rib barely upon the centrum, 
mid dorsal, with both heads for the rib in the 
middle of the side of the centrum, 
late dorsal, both tubercles for the ribs on the 
lower part of the side of the centrum; the 
upper head unusually small. The centrum 
has the usual sub-trapezoidal form, 
may be considered as sacral; on one side the 
rib heads are confluent, on the other side 
they have blended into an oblong tubercle, 
which instead of being oblique is vertical, 
centrum sub-hexagonal, with a single rib-head, 
early caudal. 
late caudal centrum, becoming sub-quadrate; 
articulation for rib extending across the cen¬ 
trum from back to front. 
