A revision of the Rhoptrobothriidae (Cestoda: “ Tetraphyllidea ”) Author Jensen, Kirsten 0000-0003-0294-8471 Department of Ecology & Evolutionary Biology and the Biodiversity Institute, University of Kansas, 1200 Sunnyside Ave., Lawrence, KS 66045, USA. & jensen @ ku. edu; https: // orcid. org / 0000 - 0003 - 0294 - 8471 jensen@ku.edu Author Pen, Isabel A. M. 0000-0002-4409-8156 Department of Ecology & Evolutionary Biology and the Biodiversity Institute, University of Kansas, 1200 Sunnyside Ave., Lawrence, KS 66045, USA. & iampen @ ku. edu; https: // orcid. org / 0000 - 0002 - 4409 - 8156 iampen@ku.edu Author Caira, Janine N. 0000-0001-9597-6978 Department of Ecology & Evolutionary Biology, University of Connecticut, 75 N. Eagleville Rd., Storrs, CT 06269 - 3043, USA. janine. caira @ uconn. edu; https: // orcid. org / 0000 - 0001 - 9597 - 6978 janine.caira@uconn.edu text Zootaxa 2021 2021-07-12 4999 3 201 218 journal article 10.11646/zootaxa.4999.3.1 1175-5326 5118878 051E68AE-6A5B-44AC-8F90-AEECB8997883 Myzophyllobothrium rubrum Shipley and Hornell, 1906 ( Fig. 4A ) Type and only known host: Whitespotted eagle ray, Aetobatus ocellatus (as Aetobatis [sic] narinari ) ( Myliobatiformes : Aetobatidae ). Type locality: Puttalam Lake , Sri Lanka (as Ceylon) . Additional localities: None. Site of infection: Spiral intestine. Specimens examined: BMNH nos. 2006.7.14.1–3, three slides identified by Southwell (1925) as Myzophyllobothrium rubrum (see Jensen and Caira 2006 ). Sequence data: None. Remarks. Joyeux and Baer (1961) resolved the issue surrounding the two different interpretations of the scolex of this species presented by Shipley and Hornell (1906) . In their figure of the scolex of one of the co-types of the species, Joyeux and Baer (1961 ; fig. 290) illustrated the anterior region of the scolex to clearly consist of four biloculate bothridia rather than four simple suckers. Unfortunately, we have been unable to locate the co-types of this species. The specimens of M. rubrum on the three slides examined here were reported by Southwell (1925) as having been collected from the type host and locality. Unfortunately, all of these specimens are in relatively poor condition, and include only one scolex. We did not consider this material to be of sufficient quality to allow re-description of this species. Nonetheless, given the paucity of information available on the proglottid anatomy of M. rubrum , a photograph of the posterior region of a mature proglottid of one of these specimens is presented in Fig. 4A .