Type host: Notophthalmus viridescens (Rafinesque, 1820), Eastern newt.

Other hosts: None reported to date.

Type locality: NORTH AMERICA: U.S.A.: Michigan, Douglas Lake, Sedge Point Pool, University of Michigan Biological Station.

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

Description of oocyst: Oocyst shape: ellipsoidal; number of walls: 1; wall thickness: not given; wall characteristics: smooth; L x W: 56.2 x 47.9 (55-58 x 45-49); L/W ratio: 1.2; M: absent; OR: present; OR characteristics: a compact body of scattered granules, 19-30 wide, with a centric or an acentric hyaline sphere, 12-13 wide; PG: absent. Distinctive features of oocyst: OR increases during the first 2 wk outside the host.

Description of sporocysts and sporozoite: 27.6 x 9.5 (18-34 x 8-10); L/W ratio: 2.9; SB: absent; SSB: absent; PSB: absent; SR: present; SR characteristics: composed of large granules that localize at one end of sporocyst; SZ: also lanceolate (line drawing), 18.9 x 4.7, with a centrally located N. Distinctive features of sporocysts: lanceolate shape.

Prevalence: 22 of 144 (15%) over a 2 yr period.

Sporulation: Exogenous. About 65-70% of all oocysts were in various stages of sporulation when fecal samples were collected from the hosts and 95% became fully sporulated within 24 h.

Prepatent and patent periods: Unknown. However, Barrow and Hoy (1960) noted that all infections were recovered 4 to 7 d after newts were collected.

Site of infection: Unknown. Oocysts recovered from feces.

Endogenous development: Unknown.

Materials deposited: None

Remarks: The oocysts of this species are similar to those of E. nipponensis described from C. pyrrhogaster from Japan (Matubayasi 1937), when their respective line drawings are compared (Fig. 2, Barrow & Hoy 1960; Fig. 11, Matubayasi 1937). However, the oocysts of E. nipponensis are smaller than those of E. megaresidua (50 x 34.5, L/W=1.5, vs. 56 x 48, L/W=1.2).