AND OTHEE EXTINCT BIEDS OF MAUEITIUS. 291 



can of course not be compared with the bird from Mauritius except by analogy. The 

 only truly " spurred Goose " of the Ethiopian region is Plectropterus ; but the spui' is 

 carried by the radial carpal bone and therefore is at once removed from comparison 

 with our specimen, which belonged to a rather large-sized species of Sarcidiornis, 

 and, having probably been restricted to the island of Mauritius, may be distinguished 

 as *S'. mauritianus. 



Another part of this bird consists of the somewhat incomplete left half of the 

 pelvis ; it agrees in size with that of Bernicla hrenta, consequently by inference with 

 Sarcidiornis, measuring 70 mm. from the anterior brim of the acetabulum to the 

 posterior end of the os ischii. The few characters which are preserved in this portion 

 of a pelvis agree with those of Anas and Anser and other Lamellirostres. 



8. Anas theodoei, sp. nov. (Plate XXXIV. figs. 11-17.) 



The fragment of a sternum, a pair of coracoids, eight humeri, and a pair of 

 metatarsi are referable to a Duck which was considerably larger than Nettapus 

 auritus, Anas bernieri, and Dendroci/gna, but smaller than Anas melleri, of which 

 we have a skin and breast-bone with shoulder-girdle for comparison. 



Of the sternum only the anterior portion is preserved, which is, however, sufficient 

 to show its affinities. Its width between the two lateral muscular ridges of the 

 sternum is 28 mm., i. e. slightly less than in Anas melleri and agreeing with Dendro- 

 ci/gna arcuata ; the sternum differs, however, from that of Bendrocygna by its well- 

 developed, although broken-off spina externa, by its lower keel, and lastly by the 

 much smaller and shallower entrance to the pneumatic foramen ; it differs also from 

 that of A. melleri by the lesser height of the keel, moreover by the shape and 

 direction of the anterior margin of the latter. 



The single left coracoid is in a perfect state of preservation and fits well into the 

 sternal fragment, so that it might belong to the same species, although certainly not 

 to the same individual. This coracoid differs from that of Bendrocygna by its greater 

 length, by the shape of its sternal end, and by its very smooth, almost plain ventral 

 surface. Nettapus and Anas bernieri are to be excluded on account of their much 

 smaller and shorter coracoids. The coracoid in question is much shorter than that of 

 A. melleri, but it agrees closely with the latter by its shape, and especially by the 

 almost plain ridgeless ventral surface of the shaft. 



The seven humeri are much like each other, but vary from 70 to 78 mm. in their 

 greatest length ; they are exactly of the same shape and size as those of different 

 specimens of Anas punctata, i. e. of a much smaller Duck than A. melleri. 



The two metatarsi are in a bad condition ; the right one measures 42 mm. in length, 

 indicating a bird much more short-footed than A. melleri. 



2 u2 



