_Butorides mauritianus_ Newton & Gadow, Trans. Zool. Soc. vol. XIII, p.
289 (1893).
The bones on which this species is founded are a pair of ulnae, one radius,
four metatarsi, and one coracoid. The description is as follows:--"The
bones in question are all considerably shorter than the corresponding bones
of _A. (Nycticorax) megacephala_. The metatarsi agree otherwise in every
detail with those of the latter species; this relative stoutness indicates
that they belonged to a Night-Heron or Bittern like _A. megacephala_. The
two ulnae cannot, unfortunately, be compared with those of _A.
megacephala_; their length, 110 mm., compared with the length of the
humerus of _A. megacephala_, 119 mm., shows, however, likewise that they
were those of a considerably smaller bird. The single left coracoid agrees
in all the features of its dorsal or scapular half with _A. megacephala_,
but its ventral or sternal half differs considerably, first by the much
more strongly marked ridge of the _linea intermuscularis_ on its ventral
surface, secondly by the almost straight instead of inwardly curved margin
between the _processus lateralis_ and the lateral distal corner of the
sternal articulation, thirdly by a very low but very distinct and sharp
ridge, which arises from the median margin of the coracoid, a little above
its median articulating corner. This roughness or prominent ridge is
entirely absent in _A. megacephala_ and in all other Herons which we have
been able to examine, but at least a slight indication of it occurs in an
individually varying degree in _Nycticorax_ and _Botaurus_. That this
coracoid bone belonged, however, to an Ardeine bird is clearly indicated by
its whole configuration, notably by the shape and position of the
precoracoid process, the various articulating facets at the dorsal end, and
the prominent lip on the visceral or internal surface of the median portion
of the sternal articulating facet."