1060 
MR. J. W. HULKE 01ST THE OSTEOLOGY 
1-5 s. The sacral vertebrae. 
1-5 f Tbe sacral foramina. 
P. Tbe right os pnbis. 
P'. Tbe left os pubis. 
Is. The right ischium. 
Is'. The left ischium. 
ob.p. Obturator process. 
Sy. The symphysis. 
Pm. The femora. 
cv, cv. Caudal vertebrae. 
ch. Chevron bones. 
PLATE 76. 
Fig. 1. Inferior view of sacral and lumbar vertebrae with ischia and pubis of an 
immature Hypsilophodon.** 
Is. Ischium. 
P. Os pubis. 
Fig. 2. Inferior view of lumbar and sacral vertebrae of a fully-grown Ilypsilophodon. *** 
s. Sacral vertebrae. 
LI. Last lumbar vertebra, 
a. Acetabulum. 
PLATE 77. 
The pelvic bones and right hind limb of a fully-grown Hypsilophodon j** 
For them better individual representation the artist has removed these bones slightly 
from their relative positions in the fossil. 
II. The ilium. 
Is. The ischium. 
Pra. The praeacetabular portion of the os pubis. 
Psa. The postacetabular part of the same. 
f. A foramen corresponding to that which in the Bird transmits the 
tendon of the Obturator internus muscle. 
a. The acetabulum. 
Pm. The femur. 
Fb. The fibula. 
T. The tibia. 
C. The os calcis. 
1—5 m. The metatarsal bones, 
