Cygnus immutabilis.
Cygnus olor, white young of.
Cyllo Leda, instability of the ocellated spots of.
Cynanthus, variation in the genus.
Cynipidae, proportion of the sexes in.
Cynocephalus, difference of the young from the adult; male, recognition of women by; polygamous habits of species of.
Cynocephalus babouin.
Cynocephalus chacma.
Cynocephalus gelada.
Cynocephalus hamadryas, sexual difference of colour in.