Type host: Ambystoma mavortium Baird, 1850, Barred tiger salamander.

Other hosts:Ambystoma tigrinum (Green, 1825), Tiger salamander.

Type locality: NORTH AMERICA: U.S.A.: Colorado, Weld County.

Geographic distribution: NORTH AMERICA: U.S.A.: Colorado, Indiana.

Description of oocyst: Oocyst shape: spheroidal; number of walls: 1; wall thickness: 1.0; wall characteristics: smooth, colorless, of uniform thickness; L x W: 22.3-22.1 (14-26 x 14-26); L/W ratio: 1.0 (1.0-1.1); M: absent; OR: present; OR characteristics: consisting of large granules usually in a compact mass, ~5-7, but sometimes scattered throughout oocyst; PG: absent. Distinctive features of oocyst: spheroidal shape with large OR.

Description of sporocysts and sporozoite: Sporocyst shape: lanceolate; L x W: 16.3 x 5.8 (12-19 x 4-7); L/W ratio: 2.8 (2.0-3.6); SB: present, snall, at pointed end of sporocyst; SSB: absent; PSB: absent; SR: present; SR characteristics: usually a compact spheroidal mass in center of sporocyst, but sometimes granules are more diffuse in anterior sporocyst; SZ: longer than sporocyst, crescent-shaped when within sporocyst, and arranged either side-by-side or intertwined with each other; neither a N nor RB are visible.. Distinctive features of sporocysts: the second largest L/W ratio in any amphbian coccidium, next to E. longaspora.

Prevalence: 5 of 5 (100%) A. mavortium from Colorado during each of 3 collection periods; 0 of 12 A. mavortium from New Mexico (Duszynski, et al. 1972), and 1 of 1 A. tigrinum (100%) salamanders from Indiana (Bolek 2000).

Sporulation: Unknown.

Prepatent and patent periods: Unknown.

Site of infection: Unknown. Oocysts collected from feces.

Endogenous development: Unknown.

Materials deposited: Photosyntypes of sporulated oocysts are deposited in the USNPC (No. 87489).

Remarks: Of the oocysts described from salamanders, only those of E. spherica (Schneider) and E. waltoni Saxe resemble E. urodela. Oocysts of E. spherica, redescribed by Lavier (1936), are much larger than those of E. urodela, with a mode of 35, and its sporocysts are much shorter and different in structure than those of E. urodela. Oocysts of E. waltoni, as described by Saxe (1955) are always subspheroidal, whereas those of E. urodela are distinctly spheroidal. Other differences between the 2 species include the size and shape of the OR and of the sporocysts.