AXIAL SKELETON OF THE PELECANID2. 341 
however (as in No. 1186 D in the College of Surgeons’ Museum), there are four mmbar 
vertebre and three presacral foramina. The more postaxial foramen also is smaller 
compared with its serial predecessor than is the most postaxial one of Pelecanus. 
Tue LuMBo-sacRAL VERTEBR&. 
These are generally three in number (normally the TWENTY-EIGHTH, TWENTY-NINTH, 
and THIRTIETH), and resemble those of Pelecanus in most of their characters. Some- 
times there are but two such vertebre. 
Tue SacraL VERTEBRA. 
These are but one or two! in number (from the THIRTIETH, the THIRTY-FIRST and 
THIRTY-SECOND VERTEBR&) ; and, unlike Pelecanus, the parapophysis of the second (when 
there are two) may be longer and much stronger than that of the first. Their diapo- 
physes arise at a very high (dorsal) level. 
Tue Sacro-CaupaL VERTEBRA. 
They are from four to six in number, including the THIRTY-THIRD, THIRTY-FOURTH, 
THIRTY-FIFTH, THIRTY-SIXTH, and THIRTY-SEVENTH VERTEBRA (Plate LX. fig. 3). 
They differ strikingly from those of Pelecanus in that they have their parapophyses 
quite suddenly bent up, so that they are as much differentiated off from the sacral 
vertebree as are the lumbo-sacrals in front; and there is consequently a fossa on each 
side behind the sacral parapophyses. ‘The parapophyses gradually descend postaxially, 
conjoined with the diapophyses, and being more and more inclined postaxiad. 
The last three interparapophysial spaces open widely on the dorsum of the pelvis. 
THE CauDAL VERTEBRA. 
These are seven”, apart from the pygostyle, in number. Unlike those of Pelecanus 
they increase in breadth considerably and gradually postaxiad. 
A hypapophysis does not appear till the fifth or sixth, and it is longer on the 
seventh. 
The transverse processes are longest in the sixth caudal vertebra. The pygostyle is 
long, prismatic, with a sharp dorsal ridge; it is ventrally flattened; and its ventral 
margin is very slightly concave (Plate LIX. fig. 7). 
THE PELvIs. 
This complex structure, including fifteen vertebre in its extended ankyloses, pretty 
closely resembles the pelvis of Pelecanus (Plate LX. figs. 1-3). 
Laterally viewed, however, the opening of the acetabulum is smaller, the sacro-sciatic 
foramen is longer, the obturator-foramen narrower, and the pubis more postaxially 
extended (Plate LX. fig. 2). 
‘Very rarely three, as in No. 5276 in the British Museum. 
* There are eight in No, 5278 in the British Museum. 
3A 2 
