Cairaella henrii gen. n., sp. n. (Proteocephalidea: Proteocephalinae) is described from the intestine of Norops trachyderma (Cope) (Polychrotidae) from San Pablo de Kantesiya in Ecuador. The new genus differs from the 12 other known genera of the Proteocephalinae (and all other proteocephalidean genera) by the presence of a dense network of osmoregulatory canals situated in the cortex and by the morphology of the scolex which is flattened dorsoventrally, with elongated deeply embedded suckers possessing a well-developed circular musculature situated in the anterolateral region, and by eggs with a three-layered embryophore possessing small outgrowths on its external surface. Ophiotaenia nicoleae sp. n. is described from the intestine of Thecadactylus rapicauda (Houttuyn) (Gekkonidae) from San Pablo de Kantesiya in Ecuador. This new species is characterised by the testes arranged in two fields, numbering 142-204, the cirrus-sac length representing 21-33% of proglottis width, the genital pore situated in the middle of the proglottis or slightly anteriorly, and the ovary width representing 68-88% of proglottis width. It differs from 20 of 27 Ophiotaenia species parasitic in New World reptiles by the presence of an apical organ and from the remaining species by one to several other morphological characters, such as the number of testes, diameter and shape of the scolex, position of ventral and dorsal osmoregulatory canals, or the presence of a vaginal sphincter. Both taxa represent the first record of proteocephalidean tapeworms in polychrotid and gekkonid lizards, respectively.
Ophiotaenia bonneti sp. n. is described from the intestine of the frog Rana vaillanti Brocchi, 1877 (Anura: Ranidae) from San Gerardo, Guanacaste, Costa Rica. The new species is characterized by the testes 100-177 in number, the genital pores situated anteriorly, the osmoregulatory canals overlapping the testis field, the cirrus pouch length as 15-24% of proglottis width, and the uterus with 18-32 ramified diverticula on each side. It differs from the 23 known species of the genus Ophiotaenia La Rue, 1911, parasitic in amphibians, by one to several morphological characters. It differs from O. gracilis Jones, Cheng et Gillespie, 1958, the most morphologically similar species, in the sucker diameter in % of scolex diameter and in the morphology of the eggs - funnel-like depression and embryophore closely investing the oncosphere in O. gracilis. We generally observe a very low mean prevalence of the Proteocephalidea in Neotropical amphibians (about 0.41%-3%), but in the case of some host species, the prevalence can reach up to 25%. We conclude that these cestodes exhibit a strict host specificity of the oioxene type. Ophiotaenia junglensis Srivastava et Capoor, 1980 is considered a species inquirenda. Batrachotaenia hernandezi (Flores-Barroeta, 1955) becomes Ophiotaenia hernandezi (Flores-Barroeta, 1955) comb. n., B. tigrina (Woodland, 1925) becomes O. tigrina (Woodland, 1925) comb. n. and B. ceratophryos (Parodi et Widakowich, 1916) becomes O. ceratophryos (Parodi et Widakowich, 1916) comb. n.