750 U. S&S. P. R. R. EXP. AND SURVEYS—ZOOLOGY—GENERAL REPORT. 
DenprocyenEaE.—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 bare for a con- 
siderable extent. 
Dernprocyena.—Lamellae of bill hidden by the edge. Hind toe lengthened, more than 
one-third the tarsus. Wings much rounded; first primary scarcely longer than 
the fourth. 
ANSER, Linnaeus. 
Anser, Brisson, Orn. 1760. Type Anas anser, L. 
Chen, Bor, Isis, 1822. Type Anas hyperborea, Gm. 
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 : 
Cuen.—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 ? 
Awnsrr.—Bill not so much elevated at the base as in Chen; 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. 
z : : 2 \/26 3 Sp nl ae 2 
Bie Species. Locality. — eb : Z ee | oke 2 Sa Sistem pecmen 
s = r=] I £ = sited = I 2 « = & measured, 
5 A Br ve Sr eka a a |ma|ES 
= | 
| 
I94U)| Anser hyperboreuss)|ssjesccccesesecceieses *25.00 | 16.40 5,80 3,12 | 2.62 0,42 2.10 210 |resvcceeleeceoves Skin...... 
NG 7Oli|Soa's esac Oversees ale cere Missouri river. ....| 28.00 16.60 5.50 3.06 | 2,98 0.44 2.08 CRSP sesenecal base oobn Skin... 00. 
1963 | Anser gambelii.....|...... dO. wees eveeee 28.60 | 16.30 | 5.42 2.88 3.10 | 0.52 2.00 DOL |eveciccee|ecw scene Skin. ..... 
10406 |......6 AD cevccenece Salt Lake oc cccicns. 28.00 | 16.00 | 5.50 2.40 | 2.70 0.40 1.86 1.92) | case cieveleces cone SKinsenaace 
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. 
ANSER HYPERBOREUS, Pallas. 
Snow Goose. 
Anser caerulescens, Linn. Syst. Nat. I, 1766, 198.—Cassin, Pr. A. N.S. VIII, 1856, 12. 
Anser hyperboreus, Pauvas, Spic. Zool. VI, 1767, 80, 25.—Bon. Syn. 1828, 376.—Sw. F. B. A. TI, 1831, 467.—Nurr. 
Man. I, 344.—Aup. On, Biog. IV, 1833, 562; pl. 381.—Is. Syn. 273.—Is Birds Amer. VI, 
1843, 212; pl. 381.—Eyron, Mon. Anat. 1839, 92.—Cassin, Pr. A. N. 8. VIII, 1856, 11. 
Anas hyperborea, Gu. I, 504.—Wirs. Am. Orn. VIII, 1814, 76; pl. Ixviii and Ixix. 
Anas nivalis, Forster, Phil. Trans. LXII, 1772, 413. 
Tadorna nivea, Breum, Vig Deutsch. 1831, 854. 
2 Anser albatus, Cassin, Pr. A. N.S. VIII, 1856, 41. 
Sp. Co —Adullt. 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 wings, except primary quills, white. Im- 
mature birds have the head washed with rusty. 
