The anonymous author of the manuscript "Rélation de l'île Rodrigue" (see Ann. Sci. Nat. (6) II p. 133 et seq. 1875) about the year 1830 mentions this bird as follows:--"There are not a few Bitterns which are birds which only fly a very little, and run uncommonly well when they are chased. They are of the size of an Egret and something like them." Habitat: Rodriguez Island. 2 Humeri, 2 Femora, 2 Tibiae, and 2 Metatarsi in the Tring Museum. {114} ARDEA DUBOISI NOM. NOV. _Butors ou Grands Gauziers_ Dubois, Les Voyages faits par le Sieur D.B. (1674) p. 169. L'Abbé Dubois is the only author who has, as far as I can ascertain, told us that the Island of Réunion also had a large almost flightless Heron as well as Mauritius and Rodriguez; and so feeling sure that it, like most other birds of this island, was distinct I name it after him. The translation of his original description is as follows:--"Bitterns or Great Egrets, large as capons, but very fat and good. They have grey plumage, each feather spotted with white, the neck and beak like a Heron, and the feet green, made like the feet of Poullets d'Inde (_Porphyrio_, W.R.). This bird lives on fish." Habitat: Réunion or Bourbon. {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