64 R. W. SHUFELDT, 
Fig. 23. Index digit of right pectoral limb of Branta canadensis 
(No. 18980, Coll. U. S. Nation. Mus.). Palmar aspect. Slightly enlarged. 
(A portion of the quill of a feather of the alula covers the distal phalanx, 
having been allowed to remain by the one who prepared the skeleton.) 
Total length of this digit 383 mm. 
Plate 5. 
Fig. 24. Right lateral view ofthe skull and mandible (detached) 
of a specimen of Anser albifrons gambeli, 2. Adult (No. 7327, Coll. 
U. S. Nation. Mus.). Natural size. 
Fig. 25. Right lateral view ofthe skull and mandible (detached) 
of a specimen of Branta canadensis huichinsi. Adult (No. 7357, Coll. 
U. S. Nation. Mus.). Natural size. 
Fig. 26. Superior view of the skull of a specimen of Oidemia 
perspieillata. Adult (No. 81712, Coll. U. 8. Nation. Mus.). Natural size. 
Mandible removed. Shows the post-narial mandibular enlargements which 
normally occur in this scoter. 
Fig. 27. Left lateral view of the skull and mandible (detached) 
of a Canvas-back duck (Marila valisineria). Nat. Size. Adult $ (No. 5040, 
Coll. U. S. Nation. Mus.). !) 
Fig. 28. Right lateral view ofthe skull and mandible (detached) 
of a specimen of Somateria v-nigra. Adult. Natural size (No. 7332, 
Coll. U. S. Nation. Mus.). 
Fig. 29. Superior view ofthe skull of Somateria v-nigra. Mandible 
removed. Nat. Size. Same skull as shown in Fig. 28. 
Plate.6. 
The extreme length in the case of any one of the skulls in Figs. 30 — 34 
is increased by about 2 mm, making the enlargement very slight. All 
are from adults and all from the Coll. U. S. Nation. Mus. Numbers alone 
will be given under the Figures. 
Fig. 30. Right lateral view of the skull and mandible of a 
specimen of Charitonetta albeola (No. 19035). Part of the horny mandibular 
theca has been allowed to remain attached. 
Fig. 31. Left lateral view of the skull and mandible (detached) 
of Aix sponsa (No. 192). 
Fig. 32. Right lateral view of the skull and mandible of a 
specimen of Chaulelasmus streperus (No. 17149). 
Fig. 33. Inferior or basal view ofthe skull ofa specimen of Ruddy 
Duck (Erismatura jamaicensis) (No. 11220). Mandible removed. 
1) Named for ANTONIO VALISNERI, an Italian naturalist, and it was 
Wınson who inaugurated the list of orthographic blunders made in the 
case of the specific name of this bird. 
