115
ARDEA MAURITIANA(NEWT. & GAD.)
- 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."
The following are the measurements:—
| Length of ulna | 111-112 | mm. |
| Length of metatarsus | 81-87 | " |
| Length of coracoid | 48 | " |
Habitat: Mauritius.
Although megacephala and mauritiana have been placed in Ardea and Butorides respectively, from the short, stout legs and general build, I am inclined to think that all three of these Herons belong to the genus Nycticorax.
