164 



ALECTROENAS (?) RODERICANA 



(MILNE-EDWARDS). 



Columba rodericana Milne-Edwards, Ann. Sc. Nat. (5) XIX art. 3, p. 16, pi. 12, ff. 1, ia, ib, 



HE original description of the sternum is as follows: — "It belongs to a 



JL species small in size, barely as large as T. tympanistria, but evidently 

 much better built for flight. In fact the most striking characters of this 

 sternum are the large size of the bouclier, the large size of the lateral notches, 

 and the shape of the keel, whose anterior angle is not much produced in 

 front. The coracoidal grooves are large and only slightly oblique. The lateral 

 branches detach themselves from the bone in front of the costal facets — they are 

 very widely spread, and stretch more directly outwards than in the remainder 

 of the species of the family. The lower lateral branches are equally divergent, 

 and the median blade of the posterior edge is remarkable from its enlargement. 

 The keel is moderately prominent, its anterior angle is much rounded, and does 

 not reach the level of the episternal apophysis, as is the case, as a rule, in 

 the pigeons. All these peculiarities, to which must be added the general 

 flattening of the bone which is hardly at all sloped like a roof, separate the 

 pigeon of Rodriguez very widely, not only from Erythroena and Turtur, but 

 also from Vinago. In its shape in general, by the little pronounced keel and the 

 direction of the latter, this sternum presents certain analogies to the essentially 

 arboreal species such as those of the genus Carfiofihaga, but they all differ 

 in having the space for the costal facets on the sides of the sternum much 

 more extended, the superior lateral branches larger, and the latter arising 

 further back, so that the lateral notches are smaller. Up to the present I 

 do not know any genus of the family of Columbidae in which the sternum 

 can at all be likened to that found recently in Rodriguez, and therefore in 

 all probability this fossil remainder is of yet another vanished species, which 

 I propose to call Columba rodericana.'" (Translated.) 



It is probable that Milne- Edwards's C. rodericana belonged to the 

 genus Alectroenas, and was the representative on Rodriguez of the Alectroenas 

 nitidissima of Mauritius. 1 humerus in the Tring Museum. 

 Habitat : Rodriguez. 



ic (1874). 



