OO 
THE CAMBRIDGE GREENSAND. 627 
side below the transverse process, has a narrower rounded base, and 
terminates at each end in a large subcircular concave cup, which is 
1,?; inch in diameter; below this, at the posterior end, is a large 
shield-shaped, subtriangular, rugose facet for the chevron bone, 
which is 5, inch deep and fully 1 inch wide. The measurement 
from the neural canal to the base of this facet is 1,4, inch. 
Except that they are longer, these vertebre recall closely the forms 
of some of the earlier caudal vertebra of Hucercosaurus; but the 
shape which was there seen to be characteristic of one or two ver- 
tebree only, here seems to extend throughout the series ; and though 
the centrum has in the last caudal preserved become reduced to little 
more than half the depth of the earliest, there is no indication of 
changing character, and the transverse process remains strong. The 
resemblance is close as far as it goes; but in the sacrum and dorsal 
regions the character is quite different, and Hucercosaurus has neither 
the compression of the body of the centrum nor the sharp keel, ex- 
cept in the earliest dorsal preserved. ‘These poimts of resemblance 
indicate close affinity, but do not suggest generic identity. 
Bones of the Hxtremities.— With this vertebral column were found 
four metatarsal bones. They are rather more than half the size of 
the complete metapodium which I figured in the ‘Annals of Natural 
History’ for November 1871, and regarded as probably pertain- 
ing to the fore limb. ‘The first left metatarsal is fairly perfect, 
;‘y inches long, 1,4, inch wide proximally, and 1,8, inch deep at 
the proximal end, which is imperfectly preserved. Its sides are 
concave, and it widens distally to 1,%, inch, where the articular 
face is concave from side to side, well rounded from above down- 
wards, and about ;% inch deep. The other three are the proximal 
ends of the second, third, and fourth metatarsal bones. When the 
four are placed together they measure rather over 5 inches from side 
to side, which is a greater width of foot than I should have antici- 
pated for Syngonosaurus ; but, in the absence of the larger bones of 
the hind limb, it is impossible to affirm or deny their claim to belong 
to this animal. There are also two phalanges which, from their 
shortness, may be first and second: but these also are so large, re- 
latively to the metatarsus, as to suggest doubt as to their natural 
association with them. The first is 2,5, inches wide and 1,8, inch 
deep at the proximal end; it is 2,4, inches long and 13 inch thick. 
The second phalange is 2,1, inches wide and 1,%, inch deep at the 
proximal end, is 1,%, inch long, and is compressed towards the distal 
end, so as to be there less than an inch thick. The indication of the 
fore limb is limited to the proximal end of the humerus; but the 
greater part of the bone is lost. The proximal end of the right 
humerus is not quite perfect on the radial side, but is 2,5, inches 
wide and 1,5; inch deep over the middle of the head. The ulnar 
side of the head is modified after the pattern of the crocodile, and a 
sharp ridge is prolonged down the two inches preserved of the ulnar 
side of the bone, which is compressed. The whole proximal part of 
the shaft rapidly becomes compressed distally, and as rapidly nar- 
rows from side to side; the articular head shows the character- 
