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18 wide and straight; that the ﬁfth is pointed and inclined backwards so as almost to touch the sixth; and that the seventh, on the other hand, is inclined forward and is apparently in actual contact with the tip of the sixth. The sixth spine, in particular, and to some extent the seventh, bears at its tip a discoidal expansion or co-ossiﬁed separate bone about 100 mm. in diameter and 20 mm. thick. This pad of bone is rough and without distinct surface. At ﬁrst we were inclined to regard it as the result of injury, more particularly as there is distinct evidence in the broken ribs already referred to of the animal having suffered an accident. There is another explanation, however, which appeals to us strongly, although at ﬁrst one is tempted to regard it as fanciful. May it not be that the crest of the head was attached to this pad of bone by muscles or ligaments? It has already been suggested that the crested trachodonts bore a frill which extended down the neck and into the dorsal region. It is not hard to imagine that we have here an extreme case of the same sort of thing. If the abnormal flexure of the neck were removed and the head and crest placed in natural position, the end of the crest would be considerably above and in advance of this pad of bone on the sixth dorsal vertebra. That such connection between the crest and the vertebrae existed in life is further suggested by the very considerable difference between the seventh and eighth neural spines, the latter of which is more than twice as long as the former. Again, the dislocation of the column between the seventh and eighth vertebrae suggests an association of the anterior part with the head and implies a participation in the series of events in connection with the abnormal ﬂexure of the neck whether before or after death.

Sacrum—It is quite impossible in view of the condition of the mount to state accurately the number of sacral vertebrae. There are at least six thoroughly fused centra and a seventh, partially united, which may be regarded as a sacro-caudal. The six anterior neural spines are high and wide like those of the posterior dorsals, but the seventh is