Uteropolystomoides multifalx n. comb. Synonyms: Polystoma multifalx Stunkard, 1924; Polystomoides multifalx (Stunkard, 1924); Polystoma stunkardi Harwood, 1931; Polystomoides stunkardi (Harwood, 1931); Polystomoides nelsoni Du Preez & Van Rooyen, 2015; Uteropolystomoides nelsoni (Du Preez & Van Rooyen, 2015). Taxonomy: Monogenea Bychowsky, 1937. Polystomatidae Gamble, 1896. Polystomoidinae Yamaguti, 1963. Type-host and locality: Pseudemys floridana (Leconte, 1830) from central Florida, USA [40]. Other records: Pseudemys concinna (Leconte, 1830) from Oklahoma, USA [10]; Pseudemys concinna from southern Florida, USA [36] (based on the reported geographical distribution, this should be P. floridana); Pseudemys concinna from the Ichetucknee River in Ichetucknee Springs State Park of Florida, USA. Pseudemys nelsoni Carr, 1938 from Gainesville, Florida, USA. Infection site: Oral cavity. Measurements (in micrometres): Body elongated and ellipsoid (Fig. 5A), dorsoventrally flat, 4730–10,691 (6743) long, 1761–3058 (2449) wide at vaginae, which is the widest point; position of vaginae 28–38% (32%) of total length measured from anterior end; body 2.2–3.9 (2.8) times longer than wide. Mouth surrounded by sub-ventral false oral sucker 684–1281 (962) in diameter. Pharynx 417–676 (554) long, 619–959 (783) wide. Intestine bifurcate with no diverticulae and no anastomoses extending full length of body proper, not entering the haptor and not confluent posteriorly. Posterior haptor 1130– 2043 (1459) long, 1409–2657 (2026) wide, 16–26% (22%) of body length, bearing three pairs of cup-shaped haptoral suckers equal in diameter 343–477 (419), supported by a ring of welldeveloped skeletal elements. Ovary 131–350 (233) long, 70–192 (124) wide, elongate, not lobed, positioned pretesticular. Mehlis’ glands large, surrounding the base of the oötype. Uterus, spherical sac like, containing up to 12 ovoid, operculate eggs. Of the 20 specimens, five had no eggs, four had 1, one had 2, two had 3, two had 4, two had 6, one had 7, one had 8 and two had 12. Eggs 137–269 (232) long, 137–193 (169) wide. No intrauterine development. Two lateral vaginae at the level of the ovary very prominent and big, 353–860 (565) long, bearing multiple marginal openings formed by branching vaginal canal. Vitellaria extended throughout most of body, except the ovary, uterus and genital bulb, and not entering the haptor. Stretching in between haptoral suckers, surrounding the female reproductive organs. Genito-intestinal canal, posterior to ovary. Testis 342–892 (545) long, 425–778 (632) wide, spherical, dense equatorial to post-equatorial. Vas deferens widens anteriorly to form the semen vesicle, narrowing towards genital bulb, opening in common genital opening. Genital pore opening ventral, directly posterior to intestinal ceca bifurcation, situated 18–24% (21%) of total length from most anterior point, genital bulb muscular, very big 438–847 (650) in diameter, surrounded by glandular cells, armed with a genital crown with 118–136 (125) genital spines (Fig. 5B), 83–98 (93) long. Two pairs of small hamuli (Fig. 5C) between posterior–most haptoral suckers with deep cut between handle and guard, handle 105–175 (137) long; guard 86–167 (121) long; hook 59–86 (70) long. Marginal hooklets placed as for other polystomes: pairs one and two between hamuli, marginal hooklet pairs three to five embedded in suckers, pairs six to eight between anterior suckers. Marginal hooklet pairs one 25–30 (28) long and hooklet pairs two to eight 24–29 (27) long.

Published as part of Chaabane, Amira, Preez, Louis Du, Johnston, Gerald & Verneau, Olivier, 2022, Revision of the systematics of the Polystomoidinae (Platyhelminthes, Monogenea, Polystomatidae) with redefinition of Polystomoides Ward, 1917 and Uteropolystomoides Tinsley, 2017, pp. 1-19 in Parasite (Paris, France) (Paris, France) 29 (56) on page 17, DOI: 10.1051/parasite/2022056, http://zenodo.org/record/12524501