Type host: Pseudacris streckeri Wright and Wright, 1933, Strecker's chorus frog.

Other hosts: None reported to date.

Type locality: NORTH AMERICA: U.S.A., Texas.

Geographic distribution: NORTH AMERICA: U.S.A.

Description of oocyst: Oocyst shape: irregular; number of walls: 1; wall thickness: ~0.5; wall characteristics: flexible, but encloses sporocysts tightly; L x W: 17.0 (15-19); L/W ratio: not given; M: absent; OR: absent; PG: present; number of PGs: 1 (rarely more), 1.6-2.5. Distinctive features of oocyst: single-layeres, flexible wall that tightly encloses sporocysts.

Description of sporocysts and sporozoite: Sporocyst shape: ovoidal; L x W: 103. x 7.3 (10-12 x 6-8); L/W ratio: 1.4 (1.3-1.6); SB: present as slight thickening at pointed end; SSB: absent; PSB: absent; SR: present; SR characteristics: 6.6 x 5.1 (5-8 x 4-6) composed of numerous granules, each up to 2.5 wide, but sometimes diffuse with scattered granules; SZ: 9.4 x 2.4 (8-10 x 2-3) in situ, each with 2 RBs; anterio-central RB usually spheroidal, 2.0 (1-3), while posterior RB is spheroidal, 1.7 (1-2); indistinct N located between the RBs. Distinctive features of sporocysts: large SR made up of large, coarse granules.

Prevalence: 10 of 34 (29%).

Sporulation: Presumably exogenous.

Prepatent and patent periods: Unknown.

Site of infection: Unknown, but see Remarks.

Endogenous development: Unknown.

Materials deposited: None.

Remarks: Only 2 other eimerians from anurans are described with oocyst walls thin enough to adhere to the sporocysts and that produce irregularly-shaped oocysts: G. neglecta and E. ranae. This species is distinguished from the former by its larger oocysts (17 vs. 9–10) and sporocysts (10 x 7 vs. 3.5–4). Although the oocysts and sporocysts of E. ranae are similar in size to those of E. flexuosa, the latter lacks an OR which is present in E. ranae. Upton and McAllister (1988) reported the site of infection for E. flexuosa as the intestine, but their oocysts were recovered from the feces and no attempt was made to check what organs were infected with developmental stages of this species; therefore, the site of infection is unknown.