Physaloptera sp. (Larvae) (Figs. 6 – 7) Description Based on 1 specimen. Larval body whitish, 4.17 mm long and 200 wide, with transversely annulated cuticle. Terminus of head with two lateral lips and cephalic collar formed by inflated cuticle. On either lip a sclerotized support and one terminal tooth present at upper margin. Each lip bearing two cephalic papillae and one amphid. Muscular esophagus 200 long by 30 wide; length of glandular esophagus 1.3 mm by 88 wide. Nerve ring encircling muscular esophagus at its posterior half, 162 from anterior extremity. Excretory pore near anterior end of glandular esophagus, 212 from anterior end of body. Tail conical, 142 long. Remarks The larvae of Physaloptera sp. occur mainly in the stomach of reptiles, birds, mammals and, rarely, amphibians and fish (Anderson 2000). This genus has been noted in the following South American amphibians: Hyla faber (Hylidae), Bufo marinus (Bufonidae), Adenomera marmorata, Leptodactylus caliginosus, L. mystaceus, Physalaemus signiferus, P. soaresi and Proceratophrys appendiculata (Leptodactylidae), from Brazil (BoquimpaniFreitas et al. 2001; Vicente et al. 1990), Bufo marinus and B. typhonius (Bufonidae), Colostethus marchesianus (Dendrobatidae), Hyla boans, H. fasciata, H. granosa, H. leali, H. leucophyllata, H. marmorata, Osteocephalus taurinus, Phrynohyas coriacea, P. venulosa, Phyllomedusa tomopterna, Scinax icterica and S. ruba (Hylidae), Edalorhina perezi, Eleutherodactylus cruralis, E. fenestratus, Leptodactylus bolivianus, L. leptodactyloides, L. mystaceus, L. pentadactylus, L. rhodonotus and L. lineatus (Leptodactylidae), Ctenophryne geayi and Hamptophryne boliviana (Microhylidae) and Pseudis paradoxa (Pseudidae) from Peru (Bursey et al. 2001). In Argentina, they have been reported by González and Hamann (2006 a; 2006 b) from Leptodactylus bufonius (Leptodactylidae) and Chaunus granulosus major (Bufonidae).Published as part of González, Cynthya Elizabeth & Hamann, Monika Inés, 2007, Nematode parasites of two species of Chaunus (Anura: Bufonidae) from Corrientes, Argentina, pp. 27-34 in Zootaxa 1393 on page 32, DOI: 10.5281/zenodo.17528