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

Other hosts: None reported to date.

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

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

Description of oocyst: Oocyst shape: ellipsoidal; number of walls: 1; wall thickness: thin layer of uniform thickness; wall characteristics: smooth; L x W: 38.1 x 25.3 (35-41 x 23-26) ; L/W ratio: 1.5 (1.3-1.7); M: present. 3.0 (2-4) wide, covered by a distinct MC; OR: present; OR characteristics: a large mass with no distinct shape, consisting of many small granules; PG: absent. Distinctive features of oocyst: large size, thin wall, presence of a M and MC and large amorphous OR.

Description of sporocysts and sporozoite: Sporocyst shape: navicular (slightly pointed at both ends); L x W: 18.1 x 7.4 (16-19 x 6-8); L/W ratio: 2.5 (2.1-2.8); SB: if present (?), very small and difficult to distinguish at 1 end of sporocyst; SSB: absent; PSB: absent; SR: present; SR characteristics: composed of 5-15 scattered granules; SZ: tightly packed in sporocyst, without discernible N or RN visible. Distinctive features of sporocysts: navicular shape.

Prevalence: 1 of 5 (20%) salamanders from Colorado; 0 of 12 salamanders from New Mexico, U.S.A.

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. 87486).

Remarks: Among the oocysts described from salamanders, only those of E. canaliculata Lavier, 1936 and E. propria (Schneider 1881) approach the size of E. microcapi, however, neither has a M or MC and the sporocysts of both are much longer than those of E. microcapi.