Cloacal Bones. (Post-anal Bones.)

Noble (1921) notes the occurrence of cloacal bones in several geckonid genera. He comments on the fact that very little reference appears in the literature in regard to cloacal bones and suggests that, lying free near the hemipenes and below the skin, they have often been overlooked.

Malcolm Smith (1935) states that post-anal bones and sacs are peculiar to the Geckonidae. The sacs are present in both sexes, but the bones only in the males. In those species in which the sacs are absent the bones are also absent.

The cloacal or post-anal bones themselves are readily observed in alizarin transparencies of males of both Naultinus and Hoplodactylus and resemble those figured by Noble (1921) for Coleonyx variegatus and Paragonatodes dickersoni. They are paired structures and each is a short, strongly curved, rod-like element, slightly rounded at its inner end.