The plates at the upper surface of the basal joints of the toes are quadrangular and opposite each other.
[22] See Baird, Review American Birds, I, 1864, 7, 8.
[23] Harporhynchus ocellatus, Sclater, P. Z. S. 1862, p. 18, pl. iii.
[24] C. ardesiacus, Salvin, Ibis, N. S. III, 121, pl. ii.
[25] C. pallasi, Temm. Man. d’Orn. I, p. 177.—Salvin, Ibis, III, 1867, 119. (Sturnus cinclus, var. Pallas, Zoögr. R.-As. I, 426.)
[26] S. azurea, Baird, Rev. Am. Birds, 1864, 62. (S. azurea, Swainson.)
[27] Parus meridionalis, Sclater, P. Z. S. 1856, 293.—Baird, Rev. 81.
[28] Parus sibiricus, Gmel. S. N. 1788, p. 1013.
[29] This remark applies to the Mexican race.
[30] N. rufa, Baird. (Alauda rufa, Gmelin, Syst. Nat. I, 1788, 798.)