Like those of all the members of this subfamily, the eggs are blue, spotless, and commonly brilliantly glossy.
"The Nests and Eggs of Indian Birds, Volume 1"
Allan O. Hume
In the collection certain additional labels are required, viz, labels for the order, family, subfamily, genus, species, and sometimes variety.
"Directions for Collecting and Preserving Insects"
C. V. Riley
The first subfamily is comprised of distinctively American birds.
"Bird-Neighbors"
Blanchan, Neltje