740 
U. S. P. R. R. EXP. AND SURVEYS—ZOOLOGY-GENERAL REPORT. 
Dendrocygneae. —Bill longer than the head; nearly parallel as far as the tip. Nostrils 
decidedly posterior to the middle of the commissure. Lower part of tibia hare for a con¬ 
siderable extent. 
Dendrocygna.— Lamellae of hill hidden by the edge. Hind toe lengthened, more than 
one-third the tarsus. Wings much rounded ; first primary scarcely longer than 
the fourth. 
ANS R, Linnaeus. 
Anser, Brisson, Ora. 1760. Type Anas anser, L. 
Chen, Boie, Isis, 1822. Type Anas hyperborea, Gin. 
The characters of Anser have already been given in a preceding page with sufficient detail 
not to require additions here. As defined, however, it embraces two sections, differing in the 
following points : 
Chen. —Bill high at base, the upper angle advancing far on the forehead. Width of base 
of upper mandible more than half the commissure. Lower edge of upper mandible much 
arched ; the teeth very prominent and large. Lower jaw very deep. Species A. hyperboreus, 
caerulescens ? 
Anser. —Bill not so much elevated at the base as in Clien; the commissure less curved ; the 
teeth less prominent. Lower jaw not so deep. Species, A. gambelii and frontalis. 
These characters apply pretty well to the American species, but European geese exhibit a 
very gradual transition between the two. 
Comparative measurements of species. 
Catal. No. 
Species. 
Locality. 
Length. 
Wing. 
Tail. 
Tarsus. 
Middle toe. 
Its claw 
alone. 
Bill above. 
Along gape. 
Height of 
bill at base. 
Width of 
bill at base. 
Specimen 
measured. 
1241 
*25.00 
16.40 
5.80 
3.12 
2.82 
0.42 
2.10 
2.10 
1970 
28.00 
16.60 
5.50 
3.06 
2.98 
0.44 
2.08 
2.30 
1963 
28.00 
16.30 
5.42 
2.88 
3.10 
0.52 
2.00 
2.04 
10406 
28.00 
16.00 
5.50 
2.40 
2.70 
0.40 
1.86 
1.92 
9953 
Anser frontalis. 
Fort Thorn, N. M.. 
26.00 
16.75 
5.10 
2.92 
3.00 
0.40 
1.96 
2.12 
0.96 
0.90 
Skin. 
* About. 
AHSER HYPERBOREUS, Pallas. 
Snow Goose. 
Anser caerulescens, Linn. Syst. Nat. I, 1766, 198.— Cassin, Pi\ A. N. S. VIII, 1856, 12. 
Anser hyperboreus, Pallas, Spic. Zool. VI, 1767, 80, 25.— Bon. Syn. 1828, 376.—Sw. F. B. A. II, 1831, 467.— Nutt. 
Man. II, 344.— Aud. Ora, Biog. IV, 1833, 562; pi. 381— Ib. Syn. 273.— Ib Birds Arner. VI, 
1843, 212; pi. 331.— Eyton, Mon. Anat. 1839, 92.— Cassin, Pr. A. N. S. VIII, 1856, 11. 
Anas hyperborea, Gin. I, 504 .—Wils. Am. Ora. VIII, 1814, 76; pi. lxviii and Ixix. 
Anas nivalis, Forster, Phil. Trans. LXII, 1772, 413. 
Tadorna nivea, Brehm, Vog. Deutsclil. 1831, 854. 
? Anser albatus, Cassin, Pr. A. N. S. VIII, 1856, 41. 
Sp. Ch. — Adult. Bill and legs red. Color pure white. Primary quills black towards the end, silvery bluish gray towards 
he base, where the shafts are white. The spurious quills are also bluish. Inside of wiugs, except primary quills, white. Im¬ 
mature birds have the head washed with rusty. 
