2 NEW SPECIES OF ISOSPORA (APICOMPLEXA, EIMERIIDAE) FROM OVENBIRDS (PASSERIFORMES, FURNARIIDAE) OF SOUTH-AMERICA

Two new species of Isospora were identified from the fecal contents of three species of ovenbirds from Ecuador. Oocysts of Isospora hyloctis tum n. sp. were found in 2 of 2 striped foliage-gleaners (Hyloctistes subulatus assimilis). Sporulated oocysts are ovoid, 17.5 x 16.0 (15.0- 21.0 x 14.0-19.0) mum, with a smooth, colorless bilayered wall; shape index is 1.09. No micropyle or oocyst residuum is present, but the ooc yst contains a single, large, irregular-shaped polar granule. Sporocys ts are ovoid, 12.4 x 8.0 (11.5-15.0 x 6.0-10.5) mum, with a smooth sin gle-layered wall, a nipple-like Stieda body, a small rectangular subst ieda body, and contain a round sporocyst residuum composed of uniform granules. Sporozoites are vermiform with an ovoid, posterior refractil e body larger than the anterior one and appear to be arranged side by side and tightly packed in the sporocyst. Isospora scleruri was found in 1 of 1 tawny-throated leaftosser (Sclerurus mexicanus obscurior) an d 1 of 3 black-billed leaftossers (Sclerurus caudacutus brunneus). Spo rulated oocysts are ovoid, 23.1 x 19.2 (22.0-25.0 x 19.0-20.0) mum, co lorless, with a smooth bilayered wall; shape index is 1.2. No micropyl e or oocyst residuum is present, but the oocyst contains a single larg e, spheroidal polar granule or occasionally an additional smaller pola r granule. Sporocysts are ovoid, 16 x 10 (15-17 x 10) mum, with a nipp le-like Stieda body and a prominent substieda body with a wavy lower b order; shape index is 1.6. The spheroidal sporocyst residuum is compos ed of uniform granules. Sporozoites are sausage-shaped, with a posteri or, ovoid, refractile body, and a large, ovoid, centrally located nucl eus, and appear packed side by side in the sporocyst.