210 Shufkldt, Osteology of Cereopsis nov(S-hollandice. [i^f April 



(No. 19,711, Coll. l^S. Nat. Mus.), and some, of the vertebrae, the 

 femora, hyoid, and upper part of the trachea of another adult 

 specimen (No. 19,734, Coll. U.S. Nat. Mu^) Then there are at 

 hand more or less complete skulls and skeletons of a large number 

 of Ducks ; of species of Mergansers ; of Branta, Olor, Anser, Chen, 

 Chlocphaga {hybrida and polioccphala), Cygnus, Hymenolcemus 

 malacorhynchus, Chenonetta jiihata, Dendrbcygna (two species), 

 Tachyeres cinereiis, and others. 



Skeleton of Cereopsis nov.e-hollandle. 



The Skull. — ^There is no existing form of Goose that I know 

 anything of which possesses a skull at all resembling that part 

 of the skeleton in Cereopsis. No Goose in the avifauna of North 

 America has one at all like it ; while in South America the skulls 

 of some of the Geese which have been relegated to the genus 

 Chlocphaga come nearer to it, but even in their case the similarity 

 is by no means at all close. (Fig. i, Plate XXVIII., fig. 18, 

 Plate XXX., and fig. 19, Plate XXXI.) 



For the size of the bird, the skull in Cereopsis is small, while, 

 at the same time, it is comparatively broad and massive. When 

 viewed from above, it is to be observed that the vault of the 

 cranium is smooth and rounded, with barely any evidence of the 

 presence of a mid-longitudinal furrow. This also obtains in 

 Chloephaga hybrida, but not so in Chlocphaga poliocephala, in which 

 Goose the median furrow is more pronounced. In Chenonetta 

 jubata, and, to a somewhat less degree, in Hymenolcemus malaco- 

 rhynchus, while the vault is smooth and rounded upon this view 

 of the cranium, there are likewise hemi-ellipsoidal elevations 

 present, corresponding to concavities within for the accommoda- 

 tion of the cerebral lobes. (Fig. 3, Plate XXVIII., fig. 12, Plate 

 XXIX., and figs. 17, 18, Plate XXX.) 



One of the most remarkable characters on the upper view of 

 the skull in Cereopsis is the presence of the very extensive 

 " supra-orbital depressions.'" These are rather shallow, but very 

 wide, and extend well forwards and backwards. For some 

 distance, mesially, they are separated from each other by about 

 2 millimetres — the separating surface presenting no elevation, but 

 lies in the same plane with the general superficies of the top of 

 the skull. (Fig. 18. Plate XXX.) 



Chlocphaga hybrida possesses the most elaborate supra-orbital 

 depressions. They are more profoundly sculpt and extensive in 

 this species than they are in representatives of other groups of 

 birds, where they are a common character. In this Goose they 

 are not only deep, with rugose surfaces, but they meet in the 

 middle line for over a centimetre and a half. They sweep round 

 to the parieto-frontal region posteriorly, while anteriorly they 

 are most profoundly impressed to a point on either side beyond 

 the frontal insertion, or articulation, of the lacrymal bone. The 

 free edge they create anteriorly is usually serrated and jagged. 



