| abstract | The genus Acanthonyssus is redefined. Described from the female, male, deutonyrnph and protonyrnph is a 2nd species of Acanthonyssus, A. proechimys, n. sp., off Proechimys semispinosus (type-host) and P. guyannensis. Other infrequent records include Heteroms anomalus, Sigmodon hispidus and Zygodontomys brevicauda. A new genus, Argitis (monotypic for A. oryzomys, n. sp.), is erected for an Acanthonyssus-like form off Oryzomys concolor (type-host) and O. bicolor. |