3io 



NEW YORK STATE MUSEUM 



skull from the aspect presented, and to make 

 some of its characters still more evi- 

 dent by contrast, we will place it be- 

 side the skull of Mergus, already 

 described in the early part of this 

 paper. We note the difference in the 

 form of the bill; the presence of the 

 craniofacial line in the goose, while 

 it is absent in the Merganser. Both 

 have the narrow depressions along 

 the margins of the orbits for the 

 nasal glands, but posterior to this the 

 goose has the domelike vault of the 

 cranium so characteristic of the more 

 highly organized types of the Anati- 

 dae, while we see that this region in 

 the Merganser is much flattened. 



Regarding the skull from the 

 under side, we are particularly to note 

 the difference in form of the maxil- 

 lopalatines, the palatine bodies, and 

 the pterygoids. 



As a rule, in the skull of geese the 

 osseous mandibles vary in length, but 

 are always broad and of a lamellar 

 structure ; the lacrymof rontal suture 

 is obliterated ; a descending process of 

 the lacrymal is much expanded, with 

 its flat surface directed outward; the 

 mastoidal head of quadrate double; 

 trochleae of mandibular foot of quad- 

 rate with their long axes placed 

 nearly at right angles with the long 

 axis of the skull; maxillopalatines 

 fuse in the median line for their en- 

 tire lengths, no posterior processes, 

 and the pterygoids short, straight, 

 and much larger anteriorly than they 

 are at their proximal extremities. 

 From a consideration of the skull of the ordinary goose we are 

 naturally led to an examination of that part of the skeleton in the 

 " tree ducks." To this end I have carefully comoared the cranium; 



Fig. 37 Right lateral view of the 

 skull of Branta canadensis. 

 Mandible removed. Natural size. 

 £. Drawn by the author from a 

 specimen in his own collection, now 

 in the State Museum; the goose hav- 

 ing been shot by him on the Platte 

 river, Fort Fetterman, Wyoming, 



