Tetrameres (Tetrameres) Megaphasmidiata n. sp (Nematoda : Tetrameridae), aparasite of the two-banded plover, Charadrius falklandicus, and white-rumped sandpiper, Calidris fuscicollis, from Patagonia, Argentina

Tetrameres (Tetrameres) megaphasmidiata n. sp. is described from the proven triculus of the two-banded plover, Charadrius falklandicus, and the white-r umped sandpiper, Calidris fuscicollis, from Patagonia, Argentina. The new s pecies shares with T. (T.) nouveli, T. (T.) paradisea, T. (T.) prozeskyi, T . paraaraliensis, T. (T.) cladorhynchi, and T. lobybieis the absence of the right spicule and the presence of 4 rows of somatic spines. Tetrameres (T. ) megaphasmidiata n. sp. differs from the first 4 species mainly by its lon ger left spicule. The new species can be distinguished from T. (T.,) clador hynchi by the extension of the lateral alae, the number and arrangement of the caudal papillae, and the absence of polar filaments in the eggs. Tetram eres lobybieis differs from the new species by having shorter rows of dorsa l spines and a different number and arrangement of the caudal papillae. Thi s report is the first record of a species of Tetrameres in C. falklandicus and C. fuscicollis.