In 1936 the writer obtained two collections of rust on species of Inga in the El Cayo District of British Honduras.2 These possesed abundant telia containing sessile, one-celled, colorless, thin-walled teliospores. Associated in one of the collections were pycnia with circinating uredinia, the urediniospores irregularly reticulated with prominent longitudinal ridges. The uredinia resembled the primary uredinia of Ravenelia Ingae (P. Henn.) Arthur as described in North America Flora (3). Although pycnia, primary and secondary uredinia have been described for R. Ingae, telia are unknown. The question therefore arose whether the telia of the British Honduran specimens were connected with the uredinia. If so the rust would not be a species of Ravenelia. These questions necessitated a study of collections of Ravenelia Ingae and other rusts of Inga. Through the kindness of Dr. George B. Cummlins the collections of the Arthur Herbarium have been available for study. Dr. Cummins had noted the occurrence of one-celled teliospores on a number of these specimens and he very generously has allowed me to use his notes. Forty-three collections of rust on species of Inga have been studied. Of these 15 have borne telia containing one-celled, hyaline teliospores. Of these 13 have been associated with uredinia of the type described as primary uredinia for Ravenelia Ingae. This therefore indicated that these are stages of one species and that it has been erroneously placed in the genus Ravenelia. The study also raised another question. Secondary uredinia have been described (3) for Ravenelia Ingae. It is stated that these deform the shoots and are confluent in large irregular