ERRATA.

PAGELINE
[4],2,from bottom, for procælian read procœlian.
[7],13,for Ossements read Ossemens.
[8],last line, paragraph (2), for outermost read innermost.
[10],21,for Sömmering read Sömmerring.
[11],5,
[11],13,
[14],note, for Beyerischen read Bayerischen.
[15],5,for ?zygapophyses read spinous-processes.
[17],6,from bottom, for Herman read Hermann.
[37],5,from bottom, after "spine as" insert "are"
[92],line above 'the Dentary Bone,' for Pterodactyle read Pterodactyles.
[97],11,for Günter read Günther.
[99],4,for Ichthyopteria read Ichthyopterygia.
[101],11,from bottom, for procælous read procœlous.
[102],15,for procælous read procœlous.
[111],8,for Sömmering read Sömmerring.

For epipubic bone read prepubic bone, pp. [61], [102], [109], [110], [111], and [pl. 8].

INTRODUCTION

TO THE

OSTEOLOGY OF THE ORNITHOSAURIA FROM THE CAMBRIDGE UPPER GREENSAND.

[Materials.]

The Cambridge Upper Greensand has yielded to collectors bones which illustrate nearly every part of the skeleton of the animals that are commonly named Pterodactyles. Large collections have been acquired for the Woodwardian Museum. A series of more than 500 bones have been arranged to exemplify the osteology and organization of the Ornithosauria in the area when the Cambridge Greensand was deposited. And this memoir is written to explain briefly some of the structures of the soft and hard parts of those animals which are exhibited or demonstrated by these relics. Another collection of nearly 400 bones has been arranged, which displays in association, as they were found entombed in the old Greensand sea-bed, the remains of the skeletons of thirty-three animals of the Pterodactyle kind. The whole of the remains from this formation hitherto gathered cannot be computed to have pertained to fewer than 150 individuals, which indicate a new sub-class of animals, two new genera and at least twenty-five new species.