Type host: Tamias striatus (Linnaeus, 1758), Eastern chipmunk.

Type locality: NORTH AMERICA: United States, Pennsylvania, Armstrong County, 40º 54' 35" N, 79º 31' 30" W.

Geographic distribution: NORTH AMERICA: United States.

Description of oocyst: Oocyst shape: ovoid; number of walls: 2; wall thickness: ~1.8; wall characteristics: outer rough/pitted, striated in cross section, yellow-brown, ~3/4 of total thickness, inner smooth and colorless; L x W: 18.6 x 14.5 (16-23 x 12-17); L/W ratio: 1.3 (1.0-1.5); M: absent; OR: absent; PG: present, 0-2; Distinctive features of oocyst: oocyst wall is occasionally thin at the narrow end.

Description of sporocysts and sporozoites: Sporocyst shape: ellipsoid; L x W: 8.6 x 5.4 (7-10 x 4-8); L/W ratio: 1.6 (1.3-2.0); SB: present, usually small and clear; SSB: may be present; PSB: absent; SR: present; SR characteristics: usually 2 or more clustered granules or rarely dispersed granules; SP: each with 1 o2 rounded RB. Distinctive features of sporocyst: none.

Prevalence: 25 of 41 (74%).

Sporulation: Exogenous. Oocysts sporulated in 2% (w/v) aqueous potassium dichromate solution at RT.

Prepatent and patent periods: Unknown.

Site of infection: Colon.

Materials deposited: Photosyntypes deposited in the USNPC no. 89751.

Remarks: Of 3 species described from marmotine rodents that do not posess a M and have a rough outer wall (E. berkinbaevi, E. lateralis, and E. ovata), E. tamiensis differs from them all by being considerably smaller in length and width.

References: Seville and Patrick (2001).