Ascaridoid species occurring in lizards and previously included in Amplicaecum are
relegated to a new genus whose morphological features are defined. In spite of some
diversity in relative length of spicules among the specimens examined, this was not
correlated with host, location, or with existing species names. Accordingly, one species
(R. varani) is recognized, other species names (iguanae, monitor, and mackerrasae)
are regarded as synonyms.